Dual sensor system for continuous blood pressure monitoring during transcatheter heart valve therapies

ABSTRACT

Dual sensor system for continuous blood pressure monitoring during transcatheter heart valve therapies (TVT), such as transcatheter aortic valve replacement (TAVR) or transcatheter mitral valve replacement (TMVR), comprises a controller, a support guidewire for TVT containing a first Fabry-Pérot (FP) optical pressure sensor near its distal end, and a pigtail catheter for delivery of contrast medium containing a second FP optical pressure sensor near its distal end. For example, for TAVR, the support guidewire is positioned to place the first optical pressure sensor within the left ventricle (LV) for monitoring LV pressure, the pigtail catheter is positioned in the aorta to place the second optical pressure sensor in the ascending aorta for direct measurement of pressure in the aorta, downstream of the aortic valve, enabling continuous monitoring of blood pressure at both sensor locations during TAVR. The controller may be configured to interface with standard patient monitoring systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. provisional PatentApplication 62/585,757, filed Nov. 14, 2017, entitled “Dual SensorSystem for Continuous Blood Pressure Monitoring During TranscatheterHeart Valve Therapies”, which is incorporated herein by reference in itsentirety.

This application is related to U.S. patent application Ser. No.15/293,380, filed Oct. 14, 2016, entitled “System and Apparatuscomprising a Multi-Sensor Catheter for Right Heart and Pulmonary ArteryCatheterization”, which is a Continuation in Part of U.S. patentapplication Ser. No. 14/874,604, filed Oct. 5, 2015 (now U.S. Pat. No.9,504,392), which is a Continuation of U.S. patent application Ser. No.14/354,624, filed Apr. 28, 2014 (now U.S. Pat. No. 9,149,230), which isa national stage entry of PCT International Application No.PCT/IB2012/055893, entitled “Apparatus, system and methods for measuringa blood pressure gradient”, filed Oct. 26, 2012, which claims priorityfrom U.S. Provisional patent application No. 61/552,778 entitled“Apparatus, system and methods for measuring a blood pressure gradient”,filed Oct. 28, 2011 and from U.S. Provisional patent application No.61/552,787 entitled “Fluid temperature and flow sensor apparatus andsystem for cardiovascular and other medical applications”, filed Oct.28, 2011.

This application is related to U.S. patent application Ser. No.15/001,347, filed Jan. 20, 2016, entitled “System and ApparatusComprising a Multisensor Guidewire for Use in InterventionalCardiology”, which is a Continuation-in-Part of PCT InternationalApplication No. PCT/IB2015/055240, of the same title, filed Jul. 10,2015, designating the United States; this application is also related toU.S. patent application Ser. No. 15/326,134 filed Jan. 13, 2017, whichis a national stage entry of PCT International Application No.PCT/IB2015/055240; PCT/IB2015/055240 claims priority from U.S.Provisional patent application No. 62/023,891, entitled “System AndApparatus Comprising a Multisensor Support Guidewire for Use inTrans-Catheter Heart Valve Therapies”, filed Jul. 13, 2014 and from U.S.Provisional patent application No. 62/039,952, entitled “System andApparatus Comprising a Multisensor Support Guidewire for Use inTrans-Catheter Heart Valve Therapies”, filed Aug. 21, 2014.

TECHNICAL FIELD

The present invention relates to a system and apparatus for continuousmonitoring of blood pressure using optical pressure sensors containedwithin a guidewire or a catheter for minimally invasive interventionalcardiology, including real-time blood pressure measurements duringtranscatheter heart therapies, such as transcatheter heart valvereplacement.

BACKGROUND

Percutaneous procedures for minimally invasive transcatheter heart valvediagnosis, repair and replacement avoid the need for invasive open-heartsurgery. These minimally invasive procedures may be referred to asTranscatheter Valve Therapies (TVT). For example, when a heart valve isfound to be malfunctioning because it is defective or diseased,minimally invasive methods are known for repair and replacement of theheart valve, by introduction of a guidewire and catheter intravascularlyinto the heart, e.g. to access a heart valve and one or more chambers ofthe heart. The guidewire and catheter are then used to guide componentsinto the heart for TVT.

TVT for valve repair includes, for example, procedures such as, balloonaortic valvuloplasty (BAV), to widen an aortic valve which is narrowedby stenosis, or insertion of a mitral clip to reduce regurgitation whena mitral valve fails to close properly. Alternatively, if the valvecannot be repaired, a prosthetic replacement valve may be introduced.Minimally invasive Transcatheter heart Valve Replacement (TVR)procedures, including Transcatheter Aortic ValveImplantation/Replacement (TAVI or TAVR) and Transcatheter Mitral ValveImplantation/Replacement (TMVI or TMVR), have been developed over thelast decade and have become more common procedures in recent years. Forexample, it has been reported that the TAVR market is projected to growat 21% Compound Annual Growth Rate (CAGR) over the next 5 years, toabout 120,000 TAVR procedures per years in the United States.

As experience with TVT continues to evolve, interventional cardiologistswho perform TVT procedures provide feedback on existing systems andapparatus and continue to seek improved or alternative systems andapparatus to advance TVT, including diagnostic tools comprising opticalpressure sensors that provide real-time direct measurements within theheart of important hemodynamic cardiovascular parameters before, duringand after TVT.

The above referenced related patents and patent applications disclosemulti-sensor guidewires and multi-sensor micro-catheters for use ininterventional cardiology; all these patents and applications areincorporated herein by reference in their entirety. For example, U.S.Pat. Nos. 9,504,392 and 9,149,230 disclose multi-sensor micro-cathetersand multi-sensor guidewires in which a distal end portion containsmultiple optical pressure sensors arranged for measuring blood pressureat several sensor locations, simultaneously, in real-time. The disclosedmulti-sensor micro-catheters and multi-sensor guidewires can beconfigured for use in minimally invasive surgical procedures formeasurement of intra-vascular pressure gradients, and more particularly,for direct measurement of a transvalvular pressure gradient within theheart, for any one of the four heart valves. For example, atransvalvular measurement of pressure across the aortic valve is madewith a multi-sensor guidewire or multi-sensor catheter having opticalpressure sensors positioned upstream and downstream of the aortic valveto measure pressure, in real-time, concurrently in the ascending aortaand left ventricle, allows for assessment of aortic valve regurgitationor stenosis, before and after a TAVR procedure.

TAVR procedures are carried out in a specialized operating room which isequipped for therapeutic and diagnostic procedures, includingfluoroscopic imaging, echo-cardiographic imaging, and patientmonitoring. For minimally invasive transcatheter procedures, thisspecialized operating room is typically referred to as a cardiaccatheterization laboratory, or “Cath Lab”. For example, a small incisionis made into a femoral artery in the groin (transfemoral approach) or aradial artery in the arm (transradial approach) to allow forintroduction of guidewires and catheters, which are advanced through theaorta and into the left ventricle (LV) of the heart. Many componentsused during TAVR, such as catheters, support guidewires and valvedelivery devices are single-use, disposable medical supplies. For thisreason, unit cost is an important consideration. For reasons ofregulatory approval, and to promote user acceptance and early adoption,it is desirable that systems comprising sensor guidewires and sensorcatheters are based on related predicate devices and integrate withinexisting procedures, e.g. they can be manufactured from materialsalready approved for medical use and deployed in a similar manner toexisting guidewires and catheters for TAVR. Another consideration forreducing cost and ease of use is compatibility with existing operatingroom equipment, such as patient monitoring and display systems.

The present invention seeks to provide an improved or alternativemulti-sensor system and apparatus comprising optical pressure sensorsfor direct blood pressure measurement within the heart, e.g., formeasurement of transvalvular pressure gradients during TVT, that providefor unit cost reduction, or mitigate one or more of the above-mentionedissues, or provide an alternative solution.

SUMMARY OF INVENTION

Aspects of the present invention provide a system and apparatus formonitoring of blood pressure at two locations for use duringtranscatheter valve therapies (TVT) and for related diagnosticmeasurements of hemodynamic parameters to assess heart valve function.

One aspect of the invention provides a dual sensor system for monitoringblood pressure at first and second locations during transcatheter valvetherapy (TVT), comprising:

-   a controller;-   a sensor support guidewire for TVT comprising a tubular member    having a length extending between a proximal end and a distal end,    the distal end comprising an atraumatic pre-formed curved flexible    distal tip, the tubular member containing a first optical fiber    extending within the sensor support guidewire from an optical    input/output connector at the proximal end of the sensor support    guidewire to a first Fabry-Perot (FP) optical pressure sensor, the    first FP optical pressure sensor being positioned within a distal    region of the tubular member, near the distal tip, and a sensor    aperture in the sensor support guidewire adjacent the first FP    optical pressure sensor for fluid contact therewith;-   a sensor angiographic catheter comprising a length of multi-lumen    catheter tubing extending between a proximal end and a distal end    and comprising a first lumen and a second lumen, the distal end    comprising a preformed pigtail distal tip, and the catheter tubing    having at its proximal end a connection hub comprising a first port    for the first lumen and a second port for the second lumen, a second    optical fiber extending within the first lumen from an optical    input/output connector of the first port to a second FP optical    pressure sensor, the second FP optical pressure sensor being    positioned within a distal region of the first lumen near the distal    tip, and a sensor aperture in the sensor catheter near the second FP    optical pressure sensor for fluid contact therewith; the second port    comprising an injection port for injection of fluid into the second    lumen and the second lumen comprising a plurality of fluid apertures    for fluid ejection along a length of the distal region between the    sensor aperture and the distal tip;-   the controller comprising an optical control unit (signal    conditioner) comprising optical input/output ports for coupling to    the optical input/output connectors of the sensor support guidewire    and the sensor angiographic catheter; a light source and detector    for operating the first and second FP optical pressure sensors and    processing optical data from the first and second optical pressure    sensors to generate data indicative of blood pressure; and a    processor, memory, hardware and/or software components for    generating analog and/or digital data comprising first and second    pressure waveforms; and a communications interface comprising analog    and/or digital ports for interfacing with at least one of a patient    monitoring system and other peripherals.

The first and second FP optical pressure sensors are preferably twomatched optical pressure sensors, i.e. a pair of similar FPMicro-Opto-Mechanical System (MOMS) sensors. These optical pressuresensors comprise, for example, standard optical fibers of 0.155 mmdiameter and FP MOMS pressure sensors of 0.260 mm diameter at the sensorend of the optical fiber for sensing pressure. Smaller or biggerdiameter optical fibers and sensors may be used as needed.

In the following description, the TVT support guidewire containing thefirst FP optical pressure sensor will be referred to as the ‘TVT sensorsupport guidewire’ or simply the ‘sensor guidewire” and the angiographiccatheter containing the second FP optical pressure sensor will bereferred to as the ‘sensor angiographic catheter’ or simply the “sensorcatheter”.

In one embodiment, the system comprises a dual optical pressure sensorsystem which is configured to enable continuous direct monitoring ofblood pressure in the left ventricle and in the ascending aorta, havingapplicability for measurements of hemodynamic parameters during TAVR. Inthis embodiment, the first FP optical pressure sensor (P1) is locatednear the atraumatic distal tip of the sensor support guidewire forpositioning of P1 within the left ventricle during TAVR. For example,the flexible distal tip comprises a preformed curved tip and the firstFP optical pressure sensor is positioned in a distal region of thesensor guidewire close to the flexible distal tip, or a few centimetresfrom the tip, to allow for placement of the FP optical pressure sensorin a central region of the left ventricle. An atraumatic flexible tip,such as a preformed J-tip, spiral tip, or other curved tip, provides foranchoring of the distal end of the sensor guidewire firmly in the leftventricle during TAVR, while reducing risk of tissue trauma orperforation of the left ventricle.

The sensor catheter takes the form of a dual lumen pigtail catheterhaving a plurality of apertures in the second lumen near the pigtail tipfor injection of contrast medium into the LV and the aorta, and thesecond FP optical pressure sensor (P2) is located in a distal region ofthe first lumen of the sensor catheter, a small distance from thepigtail tip for positioning of P2 in the ascending aorta, downstream ofthe aortic valve, during TAVR. For example, the second pressure sensoris positioned adjacent a sensor aperture in the first lumen about 2 to 7cm from the pigtail tip of the sensor catheter, and a number ofapertures, e.g. 5 to 12 apertures, in the second lumen are providedcloser to the tip for distributed injection of contrast medium into theLV or the aorta near the aortic valve.

For example, for monitoring of an aortic transvalvular pressuregradient, the first and second FP optical pressure sensors are a pair ofsimilar FP optical pressure sensors configured for measuring a bloodpressure gradient across the aortic valve during TAVR in a range of 0mmHg to 60 mmHg within ±10 mmHg or less.

In another embodiment, the dual sensor system is configured formeasurements of hemodynamic parameters during TMVR, wherein: the firstFP optical pressure sensor (P1) is a distance L1 from the flexibledistal tip of the sensor support guidewire for positioning of P1 withina first heart chamber on one side of the mitral valve during TMVR; thesecond FP optical pressure sensor (P2) is located in a distal region ofthe first lumen of the sensor catheter, a distance L2 from the pigtailtip for positioning of P2 in a second heart chamber, on an opposite sideof the mitral valve during TMVR; and said plurality of apertures in thesecond lumen near the pigtail tip are provided for injection of contrastmedium into the second heart chamber.

For example, for monitoring of a mitral valve pressure gradient, thefirst and second FP optical pressure sensors are a pair of similar FPoptical pressure sensors configured for measuring a blood pressuregradient across the mitral valve during TMVR in a range of 0 mmHg to 20mmHg within ±2 mmHg or less.

In some embodiments, optical input/output connector of the sensorsupport guidewire comprises a flexible optical coupling which isconnected to the proximal end of the sensor guidewire by a separableoptical connector. For over-the-guidewire mounting of components, forexample a valve delivery device during a TAVR, from the proximal end ofthe sensor guidewire, the optical connector comprises a micro-connector,wherein the sensor guidewire comprises a male part of the opticalmicro-connector having a diameter no greater than the outside diameterof the sensor guidewire. The sensor guidewire has physicalcharacteristics required of a TAVR support guidewire. For example,typically, characteristics of a TAVR support guidewire include a highstiffness, (e.g. a flexural modulus similar to that of an Amplatz™ ExtraStiff or Super Stiff guidewire, Confida™ Brecker guidewire or Safari™guidewire), a nominal/standard outside diameter of 0.89 mm (0.035 inch)and, for a transfemoral approach, a length of 260 mm to 300 mm to allowfor over-the-guidewire mounting of a valve delivery device and valvecomponents. The flexible optical coupling provides a low cost opticalconnection (e.g. a simple optical fiber cable) that extends from thefemale part of the optical micro-connector, that forms a connectorhandle, to an optical connector at the proximal end of the flexibleoptical coupling for connection to the controller.

In some embodiments, the sensor catheter has the form of a conventionalsmall diameter pigtail catheter used to inject a measured volume (bolus)of contrast agent into the aorta or LV through a plurality of aperturesin the sensor catheter near the aortic valve, to allow fluoroscopicimaging of blood flow in the region of the aortic valve and for imagingto check for aortic regurgitation. The sensor catheter is a multi-lumencatheter, for example a dual lumen catheter with a port for each lumen.The first lumen accommodates the second FP optical pressure sensor andits optical fiber, and a second lumen provides for fluid injection ofcontrast agent, saline solution, or other fluids. Thus, the proximal endof the dual-lumen sensor catheter comprises a connection hub, throughwhich each lumen of the multi-lumen sensor catheter is connected througha length of flexible tubing to the corresponding individual proximalport. One proximal port is provided for the optical input/outputconnector for the optical pressure sensor, and one proximal port isprovided for connection to a fluid delivery injector for injection ofcontrast agent. For example, the sensor catheter has an outside diameterof 4 to 7 French, e.g., 5 French (1.7 mm/0.066 inch), and the secondlumen has a diameter large enough to allow for rapid injection of abolus of contrast medium, e.g. ˜1 mm diameter. The second lumen may alsobe sized to allow for the introduction of a guidewire for insertion ofthe sensor catheter into the aorta or other blood vessel over theguidewire. The first lumen can be smaller, i.e. sized to accommodate thesecond optical fiber and the second optical pressure sensor, e.g. ˜0.3mm diameter.

Optionally, the sensor catheter may comprise one or more additionallumens, and the connection hub comprises a corresponding number ofports, for other purposes.

The sensor support guidewire may comprise a marker near the FP opticalpressure sensor to assist in positioning the FP optical pressure sensorin use, e.g. radiopaque markers that can be visualized by conventionalradio-imaging techniques. A marker is provided near the FP opticalpressure sensor in the sensor catheter, and a marker may be provided atthe distal tip of the sensor catheter. If required, markers may also beplaced at regular intervals along the length of the sensor catheter andsensor guidewire, so that, in use, relative positioning or spacing ofthe FP optical pressure sensors of the sensor catheter and the sensorguidewire can be determined.

Embodiments of the system and apparatus of the present invention,comprising dual FP optical pressure sensors, provide for continuousdirect monitoring of blood pressure at two locations, e.g. within theaorta and left ventricle, or within two chambers of the heart, fordiagnostic measurements during TVT procedures, such as TAVR or TMVR,including e.g., measurements of transvalvular pressure gradients before,during and after deployment of a prosthetic heart valve.

In an embodiment, the controller comprises an optical control unit,which may be referred to as a signal conditioner, comprising a lightsource and detector, and an optical interface for coupling, viarespective optical input/output ports, to each of the optical fibers andFP optical pressure sensors of the sensor catheter and the sensorsupport guidewire; data storage and processing means configured forprocessing optical data indicative of pressure values, and outputtingdigital and/or analog signals to ports of a communications interface,for coupling to a patient monitoring system and other peripherals, suchas those typically found in a Cath Lab, to display pressure waveformsand associated hemodynamic data derived from the pressure data. Forexample, where a patient monitoring system or patient care monitor (PCM)is configured for receiving analog signals indicative of blood pressurecompliant with the ANSI BP-22 Standard, the system controller comprisesa BP-22 signal converter that provides ports for respective analogsignal outputs from each of the two FP optical pressure sensors,together with the required control signals, i.e. the excitation signaloutput and sense signal input. The optical control unit comprising thesignal conditioner may be integrated with, or be a separate module, fromthe interface/link unit which converts digital outputs from the opticalcontrol unit to provide said analog signals. Additionally, oralternatively, the optical control unit comprises ports for digitalinputs and outputs, e.g. for wired or wireless coupling of thecontroller to a digital patient monitoring system and other peripherals,such as a network device or user device, e.g., a server, personalcomputer, or tablet which provides a user interface and/or data storageand analysis.

For a system configured for left heart catheterization, e.g. TAVR, inaddition to displaying pressure waveforms from the aorta and the leftventricle, the system may provide for display a plurality of numericvalues such as peak pressures, mean pressures, peak-to-peak pressuredifferentials for each curve, and pressure differentials or gradients,e.g., between the aorta and the left ventricle. The system may alsocompute a parameter such as an aortic regurgitation index (ARi), anddisplay the ARi value in real time. Where the controller comprises ananalog interface providing blood pressure signals to a BP-22 compliantpatient monitoring system, display of pressure waveforms, analysis ofdata and display of related numeric data and parameters may be performedby the patient monitoring system.

Another aspect of the invention provides a computer program productembodied as a non-transient computer readable medium storinginstructions, for execution in a processor of a controller for a dualsensor apparatus comprising a sensor guidewire containing a first FPoptical pressure sensor and a sensor catheter containing a second FPoptical pressure sensor, for processing optical data receivedconcurrently from the first and second FP optical pressure sensors, saidoptical data being indicative of blood pressure. Optionally, saidinstructions further provide for processing and displaying, on agraphical user interface, pressure waveforms and numeric data relatingto selected hemodynamic parameters and indexes.

Another aspect of the invention provides a sensor support guidewire forinterventional cardiology comprising a tubular member having a lengthextending between a proximal end and a distal end, the distal endcomprising a flexible distal tip, the tubular member containing anoptical fiber extending within from an optical input/output connector atthe proximal end of the sensor guidewire to a first FP optical pressuresensor, the first FP optical pressure sensor being positioned within adistal region of the sensor guidewire, near the distal tip, and a sensoraperture in the tubular member adjacent the first optical pressure forfluid contact therewith. In some embodiments the tubular membercomprises an outer tubular member (outer tube) and an inner tubularmember (inner tube or core tube), the inner tubular member beinginserted within the outer tubular member. The inner and outer tubularmembers of this “tube-in-tube” construction are configured to providerequired physical characteristics along the length of the sensorguidewire, e.g., stiffness, flexibility, and torque characteristics.

For use as a support guidewire for TVT, e.g. for TAVR or TMVR, thesensor guidewire is a stiff guidewire, e.g. having a stiffness similarto that of a standard support guidewire, such as an Amplatz™ Super Stiffsupport guidewire. A stiff distal region of the sensor guidewireprovides a rail that can support a valve delivery device and valvecomponents mounted over the TVT sensor support guidewire, i.e. for“over-the-guidewire” delivery and deployment.

For example, in the support guidewire, the first FP optical pressuresensor and its optical fiber are inserted into the inner tubular member,which may comprise a first stainless steel hypotube having physicalcharacteristics providing a predetermined stiffness and flexibility toact as a core of the sensor guidewire, and then the inner tubular memberis inserted into the outer tubular member. The outer tubular member maycomprise one of: a second stainless steel hypotube which is moreflexible (e.g. a laser cut hypotube); a flexible spiral woundmicro-coil; and a combination thereof. In an embodiment, the innertubular member acts as a core tube to provide a required stiffness alongthe length of the sensor guidewire, and the outer tubular member may bemore flexible along most of its length. At the sensor position, wherethe inner tubular member has an aperture or is partially cut away toform an opening or cavity around the optical pressure sensor, the outertubular layer, which itself has sensor aperture, comprises a reinforcedstiffer region around the sensor aperture adjacent to the sensor.

The tube-in-tube construction facilitates fabrication of the sensorguidewire. For example, where the sensor guidewire comprises an innertube and a more flexible outer tube, the optical fiber and FP opticalpressure sensor are inserted into the inner tube from an opening at thedistal end or through the sensor aperture, and the fiber is adhesivelysecured within the inner tube near the sensor to hold the sensor in thesensor location adjacent the aperture for fluid contact. The FP opticalpressure sensor and its fiber is then protected within the inner tubewhile the inner tube is inserted into the more flexible outer tube.

The atraumatic flexible tip of the sensor guidewire may comprise anouter flexible coil wire and an inner core wire, which are configured toprovide a desired flexibility and shape. The flexible tip may have apre-formed curved shape, such as a spiral tip. If the components of theflexible tip are not formed integrally with the inner and/or outertubular layers, the components of the flexible tip may be attached tothe inner and/or outer tubular layers by suitable means, such as one ormore of adhesive bonding, soldering, brazing, and welding, to provide asmooth transition between the sensor region of the sensor guidewire andthe flexible tip. The flexible tip may have the same outer diameter asthe sensor region of the sensor guidewire, or the tip may taper to asmaller diameter.

In some embodiments, the sensor guidewire further comprises a secondoptical pressure sensor and second optical fiber contained within theinner tubular member, the second optical pressure sensor beingpositioned proximally of the first optical pressure sensor. In a dualsensor guidewire, adjacent to each FP optical pressure sensor position,the inner tubular member has an aperture or is partially cut away toform a cavity around the optical pressure sensor, and the outer tubularlayer comprises a stiffer, reinforced region around the apertureadjacent to each sensor. In an embodiment, the dual sensor guidewire maybe configured for TAVR or TMVR.

Another aspect of the invention provides an angiographic sensor cathetercomprising a length of multi-lumen catheter tubing extending between aproximal end and a distal end and comprising first and second lumens,the distal end comprising a preformed distal tip, the catheter tubinghaving at its proximal end a connection hub comprising corresponding afirst port for the first lumen and a second port for second lumen; thefirst port for the first lumen providing an optical input/outputconnector, an optical fiber extending within the first lumen from theoptical input/output connector to an FP optical pressure sensorpositioned within a distal region of the sensor catheter near the distaltip, and an aperture in the first lumen near the FP optical pressuresensor for fluid contact therewith; the second port comprising aninjection port for injection of fluid into the second lumen, and thesecond lumen comprising a plurality of apertures near the distal tip,e.g. in a distal region between the sensor aperture and the distal tip.

Yet another aspect of the invention provides a kit comprising componentsfor use with a dual sensor system for monitoring blood pressure at firstand second locations during transcatheter valve therapy (TVT),comprising:

-   a first component comprising: a sensor support guidewire for TVT    comprising a tubular member having a length extending between a    proximal end and a distal end, the distal end comprising an    atraumatic pre-formed curved flexible distal tip, the tubular member    containing a first optical fiber extending within the support    guidewire from an optical input/output connector at the proximal end    of the support guidewire to a first Fabry-Pérot (FP) optical    pressure sensor, the first FP optical pressure sensor being    positioned within a distal region of the tubular member, near the    distal tip, and a sensor aperture in the sensor guidewire adjacent    the first optical FP pressure sensor for fluid contact therewith;-   a second component comprising: a sensor angiographic catheter    comprising a length of multi-lumen catheter tubing extending between    a proximal end and a distal end and comprising a first lumen and a    second lumen, the distal end comprising a preformed pigtail distal    tip, and the catheter tubing having at its proximal end a connection    hub comprising a first port for the first lumen and a second port    for the second lumen, a second optical fiber extending within the    first lumen from an optical/input output connector of the first port    to a second FP optical pressure sensor, the second FP optical    pressure sensor being positioned within a distal region of the first    lumen near the distal tip, and a sensor aperture in first lumen of    the catheter tubing near the FP optical pressure sensor for fluid    contact therewith; the second port comprising an injection port for    injection of fluid into the second lumen, and the second lumen    comprising a plurality of fluid apertures along a length of the    distal region between the sensor aperture and the distal tip; and-   wherein the first and second FP optical pressure sensors are pair of    similar FP optical pressure sensors.

For example, the first and second FP optical pressure sensors areconfigured for measuring a transvalvular blood pressure gradient acrossan aortic valve during TAVR, in a range of 0 mmHg to 60 mmHg within ±10mmHg or less. As another example, the first and second FP opticalpressure sensors are configured for measuring a transvalvular bloodpressure gradient across a mitral valve during TMVR, in a range of 0mmHg to 20 mmHg within ±2 mmHg or less.

Thus, systems and apparatus comprising dual FP optical pressure sensorsaccording to embodiments of the present invention provide for diagnosticmeasurements and monitoring of hemodynamic parameters, includingmeasurement of blood pressure concurrently and continuously at twodifferent and variable locations, e.g. within the aorta and leftventricle during TAVR. Accordingly, dual sensor systems may be providedwherein the sensor locations are configured for use during other TVT,such as TMVR, BAV, or for diagnostic measurements during left heartcatheterization.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription, taken in conjunction with the accompanying drawings, ofembodiments of the invention, which description is by way of exampleonly.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, identical or corresponding elements in the differentFigures have the same reference numeral.

FIG. 1 illustrates schematically a system of a first embodiment,comprising a controller, a support guidewire containing a firstFabry-Perot (FP) optical pressure sensor (sensor support guidewire), amulti-lumen angiographic catheter containing a second FP opticalpressure sensor (sensor catheter), wherein the sensor support guidewireand the sensor catheter are optically coupled to the controller, and thecontroller is connected to a patient monitoring system linked to a largescreen display;

FIG. 2 shows an enlarged schematic longitudinal partial cross-sectionalview of the sensor guidewire of the first embodiment, e.g., configuredfor measuring blood pressure in the left ventricle (LV) during TAVR;

FIGS. 3A, 3B and 3C show enlarged axial cross-sectional views of thesensor guidewire illustrated in FIG. 2 taken, respectively, throughplanes A-A, B-B and C-C of FIG. 2;

FIG. 4 shows an enlarged schematic longitudinal cross-sectional view ofthe sensor catheter of the first embodiment, configured for measuringblood pressure in the ascending aorta during TAVR;

FIGS. 5A and 5B show enlarged axial cross-sectional view of the sensorcatheter illustrated in FIG. 4 taken, respectively, through planes A-Aand B-B of FIG. 4;

FIGS. 6A and 6B show enlarged axial cross-sectional views throughmulti-lumen sensor catheters comprising two lumens of alternativeembodiments;

FIG. 7 shows an enlarged schematic longitudinal partial cross-sectionalview of a sensor guidewire of a second embodiment, comprising two FPoptical pressure sensors configured for diagnostic measurements of bloodpressure at two locations, e.g. in the ascending aorta and in the leftventricle (LV) during left heart catheterization;

FIGS. 8A, 8B, 8C and 8D show enlarged axial cross-sectional views of thesensor guidewire illustrated in FIG. 7 taken, respectively, throughplanes A-A, B-B, C-C and D-D of FIG. 7;

FIGS. 9A and 9B show two schematic side views of a 3-dimensionalpre-formed flexible tip of a helical form which may be used with sensorguidewires of the first and second embodiments;

FIGS. 10A and 10B show two schematic side views of a 3-dimensionalpre-formed flexible tip of a tapered helical form;

FIG. 11A shows a schematic block diagram of components of a controllercomprising first and second channels for a dual sensor system of anembodiment such as illustrated in FIG. 1, comprising sensor inputs anddigital and analog interfaces comprising BP-22 analog signal ports forcoupling to a BP-22 compliant patient monitoring system and FIG. 11Bshows a schematic block diagram showing details of components of onechannel of the controller;

FIG. 12 shows a schematic diagram to illustrate deployment of a dualsensor system of the first embodiment for measurement of pressure in theascending aorta (Ao) and the left ventricle (LV) in which the userinterface is displaying pressure waveforms and hemodynamic parametersincluding an aortic regurgitation index (ARi) indicative of a) a healthyheart and b) a heart with significant aortic regurgitation;

FIG. 13 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the sensor catheter and sensor supportguidewire of the dual sensor system of the first embodiment fordiagnostic measurements of hemodynamic parameters, wherein the sensorguidewire is positioned for continuous blood pressure measurement withinthe left ventricle (LV) and the sensor catheter is positioned forconcurrent and continuous measurement of blood pressure within theascending aorta;

FIG. 14 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the dual sensor support guidewire ofthe second embodiment for diagnostic measurements of hemodynamicparameters, wherein the sensor support guidewire is positioned forcontinuous blood pressure measurement within the left ventricle (LV) andfor concurrent and continuous measurement of blood pressure within theascending aorta (e.g., transfemoral approach);

FIG. 15 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the sensor catheter and sensorguidewire of the dual sensor system of the first embodiment formeasurements of hemodynamic parameters, including concurrentmeasurements of blood pressure in the LV and ascending aorta during TAVR(e.g., trans-femoral approach);

FIG. 16 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the sensor catheter and sensorguidewire of the dual sensor system of the first embodiment formeasurements of hemodynamic parameters, including concurrentmeasurements of blood pressure in the LV and RA during TMVR, in whichthe sensor guidewire passes through the apex of the heart (apicalapproach);

FIG. 17 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the sensor catheter and sensorguidewire of the dual sensor system of the first embodiment formeasurements of hemodynamic parameters, including concurrentmeasurements of blood pressure in the LV and RA during TMVR(trans-septal approach);

FIG. 18 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the sensor catheter and sensorguidewire of the dual sensor system of the first embodiment formeasurements of hemodynamic parameters, including concurrentmeasurements of blood pressure in the LV and RA during TMVR (e.g.transfemoral approach);

FIG. 19 shows a schematic partial cross-sectional diagram of a humanheart to illustrate placement of the dual sensor support guidewire formeasurements of hemodynamic parameters, including concurrentmeasurements of blood pressure in the LV and RA during TMVR(trans-septal approach); and

FIGS. 20A, 20B, 20C, 20D and 20E show views of a sensor supportguidewire for TVT according to another embodiment, to show details ofelements of a tube-in-tube construction for a single sensor supportguidewire.

DETAILED DESCRIPTION

Dual Sensor System

A schematic view of a dual sensor system 10 according to a firstembodiment, configured for continuous blood pressure monitoring, e.g.,during transcatheter heart valve replacement, is shown in FIG. 1. Thedual sensor system 10 comprises a controller 100 to which is coupled toa TVT sensor support guidewire 200, a sensor angiographic catheter 300,and peripheral equipment, e.g., a patient monitoring system 400 and auser interface 500. The TVT sensor support guidewire 200 contains afirst FP optical pressure sensor located at position P1, a distance L1from the distal end 204 of the TVT sensor support guidewire, whichcomprises a flexible distal tip 206. The sensor angiographic catheter300 is a multi-lumen catheter, e.g. a dual lumen catheter, containing ina first lumen a second FP optical pressure sensor, located at positionP2, a distance L2 from distal end 304, and having a second lumen forfluid injection, and a pigtail tip 306. The TVT sensor support guidewire200 is coupled to the controller 100 by an optical/input connectorcomprising a flexible optical coupling 208, e.g., comprising an opticalfiber within flexible tubing 223 extending between optical connector 240and optical connector 212. The sensor angiographic catheter 300 iscoupled to the controller 100 by a flexible optical coupling 308, e.g.,comprising an optical fiber within flexible tubing 343 extending betweenoptical connector 350 and optical connector 312.

In the following detailed description, for conciseness, the TVT sensorsupport guidewire 200 containing the first FP optical pressure sensorwill be referred to as the “sensor support guidewire”, or simply the“sensor guidewire”, and the sensor angiographic catheter 300 containingthe second FP optical sensor will be referred to as the “sensorcatheter”.

The controller 100 comprises first and second optical connection ports102 (i.e. 102-P1 and 102-P2) for optical connector 212 at the proximalend 202 of the flexible optical coupling 208 of the sensor guidewire 200and optical connector 312 at the proximal end 302 of the flexibleoptical coupling 308 of the sensor catheter 300. The controller 100 alsocomprises a communication interface having analog and digital portscomprising outputs for the patient monitoring system 400, otherperipherals, network devices and user devices, e.g., the user interface500 which may, for example, be a personal computer (PC) or tablet PCconnected through link 104. As illustrated schematically in FIG. 1, thecontrol unit 100 is connected through electrical connections 105 to apatient monitoring system 400, which has a link 402 to a graphicaldisplay 404, such as one of the standard large screen monitors used inthe Cath Lab or operating room. The monitoring system 400 may be part ofa standard patient monitoring system, which may be referred to as aPatient Care Monitor (PCM), or it may be a dedicated stand-alonemonitoring unit.

Referring to FIG. 1, the sensor guidewire 200 extends from the opticalconnector 240 at its proximal end to a distal end 204 comprising a softflexible tip 206, such as a pre-formed atraumatic curved tip, e.g. aspiral tip. (That is, “proximal” and “distal” are referenced relative tothe controller 100). The sensor guidewire 200 is detachably connected tothe flexible optical coupling 208 by separable optical connector 240 atits proximal end. Near its distal end, the sensor guidewire 200 containsthe first FP optical pressure sensor, at a location indicated by P1, andits optical fiber. The optical fiber extends from the optical sensorthrough the length of the sensor guidewire to the optical connector 240.A second optical fiber extends from the optical connector 240, throughthe flexible optical coupling 208 to the optical input/output connector212 at the proximal end 202 of the assembly. The sensor guidewire 200takes the form of a support guidewire for TAVR, i.e. it has suitablecharacteristics such as, stiffness, flexibility, torque characteristics,length and outside diameter to act as a support guidewire over whichheart valve components may be delivered, as will be explained below inmore detail with reference to FIGS. 2, 3A, 3B and 3C. The flexibleoptical coupling 208 does not need to have the same stiffnesscharacteristics and provides a more flexible optical coupling (e.g. asimple optical cable) between the control unit 100 and the opticalconnector 240 for connection to the sensor guidewire 200. In use, foractivation of the FP optical pressure sensor, the sensor guidewire 200is optically coupled through the flexible optical coupling 208 to thecorresponding optical input/output port 102-P2 of the optical controlunit 100. The optical connector 240 is a separable optical connector sothat the sensor guidewire 200 can be detachably connected to theflexible optical coupling 208, for activation as needed.

The sensor catheter 300 comprises a length of dual lumen catheter tubingextending from a connection hub 340 near its proximal end to a distalend 304 comprising a distal tip in the form of a preformed pigtail tip306. The connection hub 340 comprises dual ports 342 and 344. The sensorcatheter 300 has a form similar to a conventional multi-lumen catheter,in this case a dual lumen catheter, which will be described in moredetail below with reference to FIGS. 4, 5A and 5B. The FP opticalpressure sensor, indicated by position P2 is contained within the distalregion of a first lumen and its optical fiber extends through the lumen,through the connection hub 340, and through a length of flexible tubingfrom the first port 342 to an optical input/output connector 350. Asecond lumen of the sensor catheter has a plurality of apertures in thedistal region near the pigtail tip 306 and the second lumen coupledthrough connection hub 340 to a second port 344 comprising a length offlexible tubing 345 to a fluid port or connector 346 for coupling to afluid injector 348, e.g. a syringe or pump. The flexible opticalcoupling 308 comprises a flexible optical cable 343 containing anoptical fiber extending between the optical connector 350 and thecontrol unit 100, i.e. proximal end 302 of the flexible optical coupling308 is optically coupled via optical input/output connector 312 to port102-P1 of the optical control unit 100. The separable optical connector350 allows for the flexible optical coupling 308 to be disconnectedwhile the pigtail catheter is inserted and used in the normal manner.Then, optical connector 350 is connected to the sensor catheter toactivate the second FP optical pressure sensor when pressuremeasurements, e.g. in the aorta (Ao) are required. The port 344 at theproximal end which is coupled to the injector 348 provides for injectionof contrast medium, or other fluid, through the second lumen of thesensor catheter 300 to a plurality of apertures distributed radiallyalong a length of the distal region near the pigtail tip 306. The secondlumen may also provide for passing of a guidewire for introduction ofthe sensor catheter over the guidewire into the aorta or other vessel.The pigtail sensor catheter 300 may be a straight catheter, or it may bea preformed angled pigtail catheter, e.g. having a 145° or 155° angle,as indicated by 322.

The TVT sensor support guidewire 200 and its input/output opticalconnector comprising the flexible optical coupling 208 may be referredto as the sensor guidewire assembly 210. The sensor angiographiccatheter 300 and its input/output optical connector comprising theflexible optical coupling 308 may be referred to as the sensor catheterassembly 310.

The TVT sensor support guidewire assembly 210 is illustrated in moredetail in the schematic longitudinal cross-sectional view shown in FIG.2, and in schematic cross-sectional views shown in FIGS. 3A, 3B and 3C.The sensor angiographic catheter assembly 310 is illustrated in moredetail in the schematic longitudinal cross-sectional view shown in FIG.4, and schematic cross-sectional views shown in FIGS. 5A and 5B.

TVT Sensor Support Guidewire

An enlarged schematic longitudinal partial cross-sectional view of theassembly 210 comprising a sensor guidewire 200 and a flexible opticalcoupling 208, of the first embodiment, is shown in FIG. 2. The sensorguidewire 200 is configured for measuring blood pressure, e.g. in theleft ventricle (LV) during TAVR. The length of the sensor guidewire 200extends from the separable optical connector 240 at its proximal end tothe atraumatic flexible tip 206 at the distal end 204. The sensorguidewire 200 and the flexible optical coupling 208 are detachablyconnected by the separable optical connector 240. The sensor guidewire200 comprises a flexible tubular member comprising an outer tubularlayer 220 and an inner tubular layer 234. The structure and materials ofthe outer tubular covering 220 and the inner tubular layer 234 areselected to provide stiffness and other required physicalcharacteristics of a support guidewire along its length. Thistube-in-tube construction allows for the stiffness and othercharacteristics of the sensor guidewire 200 to be varied along itslength between the optical connector 240 and the distal end 204comprising the distal tip 206. For example, the inner tubular layer orcore tube 234 comprises a stainless-steel hypotube which is relativelystiff and acts as a core for the outer tubular layer 220, which may be amore flexible stainless-steel hypotube or micro-coil. The first FPoptical pressure sensor 230, at position P1, is optically and physicallyconnected to the distal end (i.e. the sensor end) of the optical fiber232, and the optical fiber 232 terminates at the proximal end (i.e.connector end) within the optical connector 240. At the sensor end ofthe fiber, a short length of protective tubing may be bonded around thesensor 230. The tubular layer 234 extends around the optical fiber 232and extends beyond the sensor end of the fiber to toward the tip 206. Inthe region of the sensor 230, there is an aperture 226 in the outertubular layer 220, and the inner tubular layer 234 is shaped to leavespace around the sensor 230, e.g., has an aperture or is cut away toform a cavity 225, to accommodate the sensor 230 and to allow for fluidcontact with the sensor 230. In this embodiment, the distal end portionof the tube-in-tube construction providing the tubular member comprisesmore flexible portions 227 of the outer tube 220, e.g. comprising alength of flexible stainless-steel micro-coil, and a reinforced stiffersection 224 of hypotube in between. As illustrated, the reinforcedregion 224 of the external tubular layer 220 extends a short length eachside of the sensor position P1, to provide a required stiffness in theregion of the sensor, i.e., where the stiffer inner tubular layer 234 iscut away to provide for fluid contact with the sensor. If required, aradiopaque marker 236 is provided near the sensor, to assist inpositioning the sensor 230 in use, e.g., by fluoroscopic imaging. Theinner tubular layer 234 extends a short distance past the sensor 230 andis bonded to the tip of core wire 239 of the flexible tip 206. Forexample, the flexible tip 206 comprises an outer flexible coil wire, andthe tip core wire 239 has a ground profile along its length, i.e. istapered to a smaller diameter, to progressively reduce stiffness of theflexible tip 206. To secure the sensor 230 in the sensor position P1next to the aperture 226, the inner core tube 234 and outer tubularlayer 220 may be secured to each other, e.g. by adhesive, filler orsolder, at points 237 at each end of the reinforced region 224. Theatraumatic flexible tip 206 may be a preformed J-tip, a preformed flatspiral tip, or a preformed 3-dimensional spiral or coiled tip, as willbe described in more detail in subsequent paragraphs. A coating, such asa hydrophilic coating, may be provided along the length of the sensorguidewire.

The sensor guidewire 200 has physical characteristics along its length,e.g. stiffness, as required of a TAVR support guidewire. For example,typically, a support guidewire for use in TAVR has a high stiffness toact as a support wire for over-the-guidewire delivery and deployment ofvalve components. An example of a guidewire used for TAVR is theAmplatz™ Super Stiff guidewire (Boston Scientific), which has beenreported to have a flexural modulus of ˜60 GPa (G. Harrison et al., J.Endovasc. Ther. 2011: 18, pp 797-801). Other guidewires used for TAVRinclude the Confida™ Brecker guidewire (Medtronic Inc.) and Safari™pre-shaped guidewire (Boston Scientific). The latter are both reportedto be stiffer than the Amplatz Super Stiff guidewire, but less stiffthan the Lunderquist® Extra-Stiff Wire Guide (Cook Medical) (˜158 GPa).

TAVR guidewires are typically available with a standard outer diameterof 0.89 mm (0.035 inch). The sensor guidewire 200 of the firstembodiment comprising the tube-in-tube construction as illustrated inFIG. 2, e.g., having an outside diameter of 0.89 mm, can readilyaccommodate a single FP optical pressure sensor 230 in an inner tube 234comprising a stainless steel hypotube having an inside diameter of e.g.,0.285 mm to accommodate the optical fiber and optical sensor. The innertube has an outside diameter (OD) which, together with the outer tubularlayer, provides required stiffness characteristics along the length ofthe sensor guidewire. For example, the inner tubular layer may be ahypotube having an OD in the range from 0.26 to 0.40 mm OD (0.014 to0.016 inch OD). The flexible tip 206 may have the same diameter as theouter tube 220 of the sensor guidewire or may be tapered to a smallerdiameter. For the transfemoral approach, the sensor support guidewire200 typically has a length in the range of about 260 mm to 300 mm. Thislength enables over-the-guidewire mounting of a valve delivery deviceand valve components. For an apical approach, i.e. through a smallincision between the ribs, directly into the apex of the left ventricleof the heart, a shorter guidewire and delivery device is typically used.For paediatric use, a sensor support guidewire of smaller dimensions maybe used, e.g. a smaller outer diameter, tip size, and smaller spacing ofthe sensor from the tip. The micro-coil and/or hypotube forming theouter tubular layer is sized to allow for an external coating whichprovides the sensor guidewire with an appropriate lubricity, e.g. ahydrophilic coating.

The optical fiber 232 extending from the optical sensor along the lengthof the sensor guidewire 200 is optical coupled through the opticalconnector 240 to a second length of optical fiber 238 in the flexibleoptical coupling 208 of the sensor guidewire. The flexible opticalcoupling 208 provides a flexible optical connection to the input/outputconnector 212 which connects to the optical input/output port 102-P2 ofthe controller 100, and it does not require the same stiffnesscharacteristics as the sensor support guidewire 200. For example, theflexible optical connection 208 of the sensor guidewire may simplycomprise a length of low cost flexible tubing 222 and a protective outerjacket 223 containing the optical fiber 238. Flexible optical connection208 has at its proximal end 202 a standard type of optical input/outputconnector 212, comprising a strain boot 219, for connection of the firstoptical pressure sensor to a corresponding port 102-P2 of the opticalcontrol system. This input/output connector 212 may be a smart connectorwhich has a memory chip or readable tag that stores a sensor ID andcalibration data, e.g. a SCAI connector comprising an EEPROM.

Preferably, the optical connector 240 connecting the sensor guidewire200 to the flexible optical coupling 208 is a separable optical couplerin which the male part of the connector is carried by the proximal endof the sensor guidewire 200, and which has a diameter no greater than amaximum outside diameter D_(g) (e.g., 0.89 mm) of the external coveringof the sensor guidewire 200. Separation of the two parts of theconnector 240 enables over-the-wire mounting of a valve delivery systemand valve components on the proximal end of the sensor guidewire 200.The female part of the optical connector 240 forms the distal end of theflexible optical connection 208. The body 241 of the female part of theconnector 240 may be of sufficient external size to form a handle formanipulating the sensor guidewire 200 to assist with pushing, pullingand twisting the sensor guidewire 200 as the sensor guidewire isinserted and withdrawn. The optical fiber connector 240 comprisesalignment means for the optical alignment of ends of the two opticalfibers 232 and 238, for example, as illustrated schematically, using apair of ferrules 243 and an alignment sleeve 242.

FIGS. 3A, 3B and 3C show enlarged axial cross-sectional views of thesensor guidewire assembly illustrated in FIG. 2 taken, respectively,through planes A-A, B-B and C-C of FIG. 2. The cross-section in FIG. 3Athrough cross-section A-A of the flexible optical connection 208 showsthe flexible tubing layer 222 surrounding optical fiber 238, and theouter protective jacket 223. The cross-section in FIG. 3B throughcross-section B-B of the TVT sensor support guidewire 200 shows theoptical fiber 232 surrounded by protective inner core tube 234 withinthe outer tube 220. The optical fiber 232 fits slidably within the innercore tube 234. For example, the core tube has an inner diameter of 0.285mm to accommodate an optical sensor of 0.260 mm diameter, and theoptical fiber is a standard optical fiber having an outside diameter inthe range from about 0.100 mm to 0.200 mm. The cross-section shown inFIG. 3C taken through cross-section C-C of the distal region of thesensor support guidewire near the sensor shows the sensor 230, theprotective inner tube 234 cut away in the sensor region to form a cavity225 and the surrounding reinforced region 224 of the outer tube 220. Anaperture 226 is provided in reinforced region 224 near the sensor 230 toallow for fluid contact with the sensor 230. The outer diameter of thesensor guidewire D_(g) is indicated in FIGS. 3B and 3C, and, forexample, is typically 0.035 inch (0.89 mm) for a guidewire for leftheart catheterization. The flexible tubing layers of flexible opticalconnection 208 shown in FIG. 3A may have any suitable diameter.

Angiographic Sensor Catheter

An enlarged schematic longitudinal partial cross-sectional view of theassembly 310 comprising a sensor catheter 300 and a flexible opticalcoupling 308, of the first embodiment, is shown in FIG. 4. The sensorcatheter 300 comprises a dual lumen pigtail catheter configured formeasuring blood pressure, e.g., in the aorta during TAVR, and forinjecting contrast medium, saline or other fluid, e.g., into the LV andthe aorta during TAVR. That is, the sensor catheter 300 has the form ofa small diameter, angiographic pigtail catheter of the type used todeliver a fluid injection of contrast agent into the aorta near theaortic valve, to allow fluoroscopic imaging of blood flow in the regiondownstream of the aortic valve and for imaging to look for aorticregurgitation. This type of catheter may be referred to as anangiographic catheter or a diagnostic catheter. However, unlike aconventional pigtail catheter used for injecting contrast medium, thesensor catheter has a first lumen 314-1 containing the optical pressuresensor 330 and optical fiber 332. As illustrated in the longitudinalcross-sectional view shown in FIG. 4, the sensor catheter 300 comprisesa length of dual lumen catheter tubing 320, extending from theconnection hub 340 to a distal end 304 comprising a pre-formed pigtailtip 306. The first lumen 314-1 accommodates the second optical pressuresensor 330 and its optical fiber 332. The optical pressure sensor 330 islocated an appropriate distance L2 from the pigtail tip 306, so that thesensor can be positioned in the ascending aorta when the pigtail tip 306is positioned close to the cusps of the aortic valve. A sensor aperture326 for fluid contact is provided in the wall of the first lumen 314-1near the sensor 330, and the first lumen 314-1 is plugged distally ofthe sensor position by plug 336. The optical fiber 332 may also besecured in the lumen 314-1 near the sensor 330, e.g. by adhesive 315. Aradiopaque marker band 311 is provided near the optical pressure sensor330, and another radiopaque marker band 311 is also provided at thedistal end 304, to assist with positioning the pigtail tip near theaortic valve. The spacing L2 between the sensor 330 and the distal end304 is selected to place the sensor 330 in the ascending aorta a fewcentimeters downstream of the aortic valve. The second lumen 314-2provides for fluid injection and has a plurality of apertures 335 whichare spaced around the circumference of the sensor catheter, along alength of the distal region of the sensor catheter near the pigtaildistal tip 306, to allow for distributed injection of contrast medium orother fluids. In the distal region beyond the sensor position and theplug 336 in the first lumen, the first and second lumens may beconnected to allow for more distributed ejection of fluid throughapertures 335. The end 316 of the second lumen 314-2 is open to allowthe sensor catheter to be inserted over a guidewire. The connection hub340 at the proximal end of the sensor catheter has a port for each lumenof the catheter tubing. The port 344 for the second lumen 314-2 forfluid injection comprises a length of flexible tubing 345 extending fromthe connection hub 340 to a standard type of fluid injection port 346for coupling to, as example, a syringe. This port also allows forinsertion of the sensor catheter into the body over a guidewire. (Aconventional port of this type may be referred to as a “tail” of thecatheter). The port 342 for the first lumen comprises another length offlexible tubing through which the optical fiber 332 extends to aseparable optical connector 350 for detachably connecting the flexibleoptical coupling 308, which comprises a length of flexible tubing 343containing an optical fiber 338 and an optical input/output connector312 for connection to the controller. The separable optical connector350 is provided near the connection hub 340 to facilitate connection anddisconnection of the flexible optical coupling 308, as needed. By way ofexample, along its length from the connection hub 340 to the pigtail tip306, the sensor catheter 300 has an outside diameter in the range ofabout 4 French to 7 French, e.g., 5 French (1.7 mm/0.066 inch).

FIGS. 5A and 5B show enlarged axial cross-sectional views of the sensorcatheter illustrated in FIG. 4 taken, respectively, through planes A-Aand B-B of FIG. 4. The cross-section of FIG. 5A shows lumens 314-1 and314-2, with optical fiber 332 within the first lumen 314-1. Thecross-section of FIG. 5B shows the sensor 330 in lumen 314-1 andaperture 326 adjacent the sensor 330 for fluid contact with the sensor330. If, for example, the sensor catheter 300 has an outer diameterD_(c) of 5 French (1.7 mm/0.066 inch), the inner diameter of secondlumen 314-2 is sized to be large enough to allow rapid injection of abolus of contrast medium into the aorta downstream of the aortic valve,e.g. 25 ml to 60 ml of contrast medium over 1 or 2 seconds whichrequires a larger lumen, e.g. ˜1 mm diameter. The inner diameter of thesecond lumen is also sized to accommodate a conventional guidewire,i.e., for introduction of the sensor catheter into the aorta or othervessel, by passing it over the guidewire. The inner diameter of thefirst lumen 314-1 is large enough to accommodate the optical fiber 332and the optical pressure sensor 330, and need not be as large as thefluid injection lumen 314-2. For example, if the sensor 330 has adiameter of 0.260 mm, the first lumen may have a diameter which providessome clearance around the sensor for insertion of the sensor into thelumen, e.g. a lumen of 0.325 mm diameter.

In variants of the dual lumen sensor catheter of the first embodimentillustrated schematically in FIGS. 4, 5A and 5B, the cross-section ofthe catheter tubing has other geometries or configurations that providefirst and second lumens of appropriate sizes. By way of example,cross-sectional views of examples of dual lumen catheters of twoalternative embodiments are shown in FIGS. 6A and 6B. Correspondingelements are numbered with the same reference numerals as those shown inFIGS. 4, 5A and 5B. Catheter tubing 320 having a cross-section as shownin FIG. 6A, with first lumen 314-1 for the optical fiber 332 and secondlumen 314-2, provides a more uniform wall thickness than thecross-section shown in FIG. 5A, to provide a sensor catheter with moreradially symmetric physical characteristics, such as flexibility andtorque steering characteristics. Catheter tubing having a cross-sectionas shown in FIG. 6B provides a similar sized lumen 314-1 for the opticalpressure sensor 330 and optical fiber 332 as the sensor cathetercross-section shown in FIG. 5A, and provides a fluid lumen 314-2 with alarger cross-sectional area. Dual lumen sensor catheters having othercross-sections may be used. Also, if required, multi-lumen sensorcatheters having one or more additional lumens for other purposes may beused, such as a central lumen for insertion of a guidewire, oradditional fluid lumens.

Dual Sensor Support Guidewire for Left Heart Catheterization

An enlarged schematic longitudinal partial cross-sectional view of asensor guidewire assembly 1210 comprising a sensor guidewire 1200 and aflexible optical coupling 1208 of a second embodiment is shown in FIG.7. The sensor guidewire 1200 of this embodiment comprises two FP opticalpressure sensors 1230-1 and 1230-2 and is configured for diagnosticmeasurements of blood pressure concurrently in two locations, e.g., inthe left ventricle (LV) and in the aorta during left heartcatheterization. Many parts of this dual sensor guidewire are similar tothose of the sensor guidewire 200 of the first embodiment and arelabeled with the same reference numerals incremented by 1000. The dualsensor guidewire 1200 extends from the optical coupler 1240 at itsproximal end to the atraumatic flexible tip 1206 at the distal end 1204.The dual sensor guidewire is coupled through the separable opticalconnector 1240 to the flexible optical coupling 1208 for connection byinput/output connector 1212 to the controller. The sensor guidewire 1200comprises a flexible tubular member comprising an outer tubular layer1220 and an inner tubular layer 1234. Like the sensor guidewire 200 ofthe first embodiment, the structure and materials of the outer tubularcovering 1220 and the inner tubular layer 1234 of the sensor guidewire1200 are selected to provide stiffness and other required physicalcharacteristics of a support guidewire along its length. For example,most of the length of the flexible tubular covering 1220 of the distalportion of the sensor guidewire 1200 comprises a stainless-steel metalhypotube having an appropriate stiffness/flexibility, while the distalend portion comprises more flexible regions 1227, which comprises alength of flexible stainless-steel micro-coil, and a reinforced, e.g.stiffer, section of hypotube 1224 in between. A first FP opticalpressure sensor 1230-1, at position P1, is optically and physicallyconnected to the distal end (i.e. the sensor end) of a first opticalfiber 1232-1 which terminates at the proximal end (i.e. connector end)of the sensor guidewire within the optical connector 1240. A second FPoptical pressure sensor 1230-2, at position P2, is optically andphysically connected to the distal end (i.e. the sensor end) of theoptical fiber 1232-2 which terminates at the proximal end of the sensorguidewire within the optical connector 1240. The inner tube 1234 extendsaround the fibers and extends beyond the sensor end of the fiber 1232-1towards the tip 1206. In the region of each sensor 1230-1 and 1230-2,there is an aperture 1226 in the outer tubular layer 1220, and the innertubular layer 1234 is shaped to leave space around the sensor, e.g. cutaway to form a cavity 1225, to accommodate the sensor 1230 and to allowfor fluid contact with the sensors 1230. As illustrated, the reinforcedregion 1224 of the outer tube 1220 extends a short length each side ofthe sensor position P1 and sensor position P2 to provide a requiredstiffness in the region of the sensors, i.e. where the inner tubularlayer 1234 is cut away. A radiopaque marker 1236 may be provided neareach sensor, to assist in locating the sensors 1230-1 and 1230-2 in use,e.g. by fluoroscopic imaging. The inner tubular layer 1234 extends ashort distance past the first sensor 1230-1 and the tip core wire 1239forms the core of the flexible tip 1206. To position each sensor 1230next to its aperture 1226 within the reinforced region 1224 of the outertubular layer 1220, the inner and outer tubular layers 1220 and 1234 maybe secured to each other, e.g. by bonding with adhesive or filler,soldering or welding, at points 1237 at each end of the reinforcedregion 1224. The atraumatic flexible tip 1206 may be a preformed J-tip,a preformed flat spiral tip, or a preformed 3-dimensional spiral orcoiled tip.

Similar to the sensor guidewire 200 of the first embodiment, if thesensor guidewire 1200 is to be used for TVT, e.g. TAVR or TMVR, thesensor guidewire 1200 has physical characteristics along its length,e.g. stiffness, required of a support guidewire to provide a rail forthe delivery device and valve components. The optical fibers 1232-1 and1232-2 in the sensor guidewire 1200 are optically coupled through thedual fiber optical connector 1240 to corresponding optical fibers 1238-1and 1238-2 in the flexible optical coupling 1208 of the sensor guidewire1200 to the controller. The dual optical fiber connector 1240 comprisesalignment means for optical alignment of the pair of optical fibers1232-1 and 1232-2 with the pair of optical fibers 1238-1 and 1238-2using a pair of ferrules 1243 and an alignment sleeve 1242 comprising analignment facet, e.g., using D-shaped ferrules and a correspondinglyshaped alignment sleeve. In use, the sensor guidewire 1200 is connectedto a flexible optical connection 1208 to the input/output connectors1212-1 and 1212-2 which connect to the optical input/output ports 102-P1and 102-P2 of the controller. For example, the flexible opticalconnection 1208 for the sensor guidewire 1200 may simply comprise alength of flexible tubing 1222, and protective outer jacket 1223containing the optical fibers 1238-1 and 1238-2. The flexible opticalcoupling 1208 of sensor guidewire 1200 differs from that of the sensorguidewire of the first embodiment because it has a connection hub 1216at its proximal end 1202, which separates the two optical fibers 1238-1and 1238-2 and provides two separate ports, each comprising a length offlexible tubing 1218 and a standard optical input/output coupler 1212-1,1212-2, such as a SCAI connector, each comprising a strain boot 1219,for connection of the first optical pressure sensor to a correspondingoptical ports 102-P1 and 102-P2 of the controller 100. If required, theoptical coupler 1240 connecting the sensor guidewire 1200 and theflexible optical coupling 1208 is a separable optical coupler 1240 inwhich the male part of the connector is provided by the sensor guidewire1200 and has a diameter no greater than a maximum outside diameter D_(g)of the external covering the sensor guidewire 1200. Separation of thetwo parts of the connector 1240 enables over-the-wire mounting of avalve delivery system and valve components on the sensor guidewire 1200.The female part of the coupler forms the distal end of the flexibleoptical coupling 1208 to the sensor guidewire 1200. The female part 1241of the optical connector 1240 may be of sufficient external size to forma handle for manipulating the sensor guidewire, e.g. to assist withpushing and pulling the sensor guidewire 1200 as it is inserted andwithdrawn. The flexible optical coupling 1208 of the sensor guidewiremay be of a larger diameter, more flexible and fabricated from lowercost components to facilitate fabrication and reduce costs.

FIGS. 8A, 8B, 8C and 8D show enlarged axial cross-sectional views of thesensor guidewire illustrated in FIG. 7 taken, respectively, throughplanes A-A, B-B, C-C and D-D of FIG. 7. The cross-section in FIG. 8Athrough the flexible optical coupling 1208 shows the flexible tubinglayer 1222 surrounding optical fibers 1238-1 and 1238-2, and the outerprotective jacket 1223. The cross-section in FIG. 8B through the sensorguidewire 1200 shows the optical fibers 1232-1 and 1232-2 surrounded byprotective inner tubular layer 1234 within the outer tubular layer 1220.The inner diameter of the inner tubular layer is sized so that the twooptical fibers 1232-1 and 1232-2 fit slidably within the inner tubularlayer 1234. The cross-section shown in FIG. 8C taken through the distalend of the sensor guidewire 1200 near the first FP optical pressuresensor 1230-1 shows the sensor 1230-1, the protective inner layer 1234cut away in the sensor region to form a cavity 1225 and the surroundingreinforced region 1224 of the outer tubular layer 1220. An aperture 1226is provided in reinforced region 1224 near the sensor to allow for fluidcontact with the sensor. The cross-section shown in FIG. 8D is takenthrough the distal end near the second FP optical pressure sensor 1230-2shows the second FP optical pressure sensor 1230-2 lying beside thefirst optical fiber 1232-1, where the protective inner layer 1234 is cutaway in the sensor region to form a cavity 1225 for the second FPoptical pressure sensor 1230-2 and the surrounding reinforced region1224 of the outer tubular layer 1220. As for the first FP opticalpressure sensor 1232-1, an aperture 1226 is provided in a reinforcedregion 1224 near the second sensor 1230-2 to allow for fluid contactwith the second sensor 1230-2. The outer diameter of the sensorguidewire Dg is indicated in FIGS. 3B, 3C, and 3D, and is e.g.,typically 0.035 inch (0.89 mm) or less for left heart catheterization.The diameter of the flexible optical coupling 1208 shown in FIG. 8A mayhave any suitable diameter.

The tip 206 and 1206 of the sensor guidewires 200 and 1200 of the firstand second embodiments is preferably an atraumatic pre-formed curved tipsuch as a pre-formed spiral tip. For example, for firmly anchoring ofthe tip of the sensor guidewires 200 and 1200 in the left ventricleduring TAVR, a 3-dimensional curved spiral tip may be preferred. Forexample, FIGS. 9A and 9B show two schematic side views of a3-dimensional pre-formed flexible spiral tip 206-1 having a helical formand comprising an aperture 226 for the FP optical pressure sensor spaceda distance L1 from the apex of the curved tip. Another example of a3-dimensional pre-formed curved flexible tip 206-2 of a tapered helicalform is shown schematically in FIGS. 10A and 10B. The radii, number ofturns and other dimensions of the spiral or helix may be selected basedon dimensions of the left ventricle. For other TVT procedures, e.g.insertion of a sensor guidewire into other chambers of the heart, e.g.the left atrium, or for an apical approach to the aorta, a flexiblepreformed curved tip of another form may be used.

Schematic views showing details of components of a TVT sensor supportguidewire 2200 of another embodiment are shown in FIGS. 20A to 20E. FIG.20A shows a schematic partially cut-away view a TVT sensor supportguidewire 2200 comprising a main body 2201 having a length L extendingbetween a proximal end 2202 comprising a fiber optic termination 2243and a sensor region 2203 near the distal end 2204. The distal endcomprises a flexible pre-formed curved distal tip 2206. FIG. 20A showsthe tapered inner core wire 2239 of the spiral distal tip, with itsouter coil removed. The main body 2201 of the TVT sensor supportguidewire comprises an inner tubular layer, which may be referred to asa core tube, 2234, extending within an outer tubular layer 2220, e.g.,as shown schematically in FIGS. 20D and 20E. In this embodiment the coretube 2234 comprise a stainless steel hypotube. The outer tubular layer2220 comprises a flexible coilwire 2220-1 covering the core tube 2234between the fiber optic termination 2243 and the sensor region 2203 ofthe sensor guidewire, and a length of stainless steel hypotube 2220-2 inthe sensor region 2203 (FIG. 20B). As shown in more detail in theenlarged view in FIG. 20B, the hypotube 2220-2 provides reinforcementand stiffness to the outer tubular layer in the sensor region 2203around the sensor aperture 2226. An enlarged view of the proximal end2202 of the sensor guidewire is shown in FIG. 20C, showing the fiberoptic termination comprising an optical input/output micro-connector2212, e.g. a ceramic ferrule 2243 surrounding the connector end of theoptical fiber 2232, and an outer sleeve 2245. The outer sleeve 2245,e.g. a length of stainless steel hypotube, extends a short distancebetween the ferrule 2243 and the flexible coil wire 2220-1 to reinforceand stiffen the proximal end of the sensor guidewire near the ferrule2243. The ferrule 2243 is configured to insert into a correspondingfemale part of an optical connector carried by a flexible opticalcoupling, such as a length of optical cable, for connecting the sensorguidewire 1200 to the optical controller 100, as illustrated for examplein FIG. 1, for sensor guidewire 200 of the first embodiment. Preferably,the ferrule 2243 and the outer sleeve 2245 have a maximum outer diametersimilar to the maximum diameter of the main body 2201 of the sensorguidewire, e.g., 0.035 inch, to allow for over-the-wire mounting of thecomponents for TVT, such as a catheter carrying a valve delivery device.An enlarged view of part of the sensor guidewire in the sensor region2203 is shown in FIG. 20D, with the outer tubular layer comprising thehypotube 2220-2 removed to show the inner core tube 2234 comprisingaperture 2226 near the FP optical pressure sensor 2230, and the corewire 2239 which forms the core of the spiral tip 2206 (FIG. 20A). Across-sectional view of the sensor region is shown in FIG. 20E to showdetails of the inner core tube 2234 and the outer sensor hypotube 2220-1near the sensor 2230. In this embodiment, inner core tube 2234 is cutaway to form an aperture 2228 in the region where the sensor 2230 isplaced and the sensor aperture or “pressure window” 2226 in the outerhypotube 2220-2 is formed by a through hole which is drilled rightthrough the sensor hypotube 2220-2 in the sensor region, to provide anaperture on each side of the sensor position.

Control System

Referring to the controller 100 shown schematically in FIG. 1, thecontroller of the dual sensor system may be used with a sensor guidewireand a sensor catheter for concurrent blood pressure measurements at twolocations. Alternatively, the same controller may be used with a dualsensor guidewire such as described with reference to FIG. 7.

For dual optical pressure sensors, the controller 100 has acorresponding number of signal processing channels with optical ports102-P1 and 102-P2 for optical connectors each of the optical pressuresensors as illustrated schematically in FIG. 11A. Each channel comprisesan optical control unit, which may be referred to as a signalconditioner, comprising an optical light source and detector foroperating a FP optical pressure sensor, associated signal processingelectronics and communications interfaces providing digital ports 132,and analog ports 134 for input/output signals to connectors for an ANSIBP-22 compliant PCM. For example, as illustrated schematically in theblock diagram in FIG. 11B, each channel of the control system comprisesa signal conditioner 110, that comprises the light source and detectorand an optical interface 112 for coupling, via respective input/outputports, to an optical fiber and FP optical pressure sensor of a sensorcatheter or a sensor guidewire. Calibration data from the sensor EEPROMis input at interface 114 to digital interface 116 which providescalibration data to the signal conditioner 110. The control system alsocomprises processing means and data storage, e.g. a microprocessor 120,and associated firmware 122, RAM 124, display and indicators 126. Thesignal conditioner 110 comprises hardware and software configured forprocessing optical data indicative of pressure values to outputcalibrated digital sensor data to the microprocessor 120. Digitaloutputs from the microprocessor 120 are provided to the digitalinterface 128 comprising standard digital ports 132 and to BP-22 signalconverter 130 which provides analog ports 134 for input/output signalsfor a BP-22 compliant patient care monitor (PCM). The system alsocomprises AC/DC power electronics 125 for these components.

Where the controller is to be interfaced to a BP-22 compliant PCM formonitoring blood pressure data, and the PCM is configured for displayingblood pressure waveforms, i.e. a pressure waveform from each opticalpressure sensor, on a graphical user interface, the concurrent bloodpressure waveforms for each of the FP optical pressure sensors may bedisplayed for one or more time intervals, and during one or more cardiaccycles. The PCM may be further configured to derive hemodynamicparameters from the blood pressure data and display numeric values ofthe parameters, such as aortic regurgitation index, as well as displaythe pressure waveforms from each sensor.

If the controller is not connected to a BP-22 compliant patient monitor,digital outputs may be provided to a digital patient monitoring systemor to a general-purpose computer 500, such as a tablet PC, runningsoftware configured to display of the pressure waveforms and associatedhemodynamic parameters. Alternatively, the microprocessor 120 of thecontroller 100 may be configured to generate digital outputs fordisplaying of blood pressure waveforms and other hemodynamic parameterson a monitor linked directly to the controller 100.

The user interface of the PC or PCM may allow the operator to input userdata such as patient identification, and data interfaces may be providedto output data to other devices or systems, or receive data from othersources, such as from other sensors or monitoring systems, which aretypically used in an ICU or OR. For example, in a cardiaccatheterization laboratory, the control system 100 for a sensor catheterand sensor guidewire may be coupled to, or part of, a computing systemcontrolling other equipment, and which is equipped with one or morelarge screen displays close to the operating table, and other remotedisplays in a monitoring area. The latter are used to display variousforms of data, sequentially, concurrently, or on demand. Such data mayinclude, e.g. fluoroscopic imaging, with or without contrast media, andtransoesophageal echo-cardiography (TEE) images, as well as sensor datacomprising pressure waveforms from the sensor catheter and sensorguidewire and associated hemodynamic parameters calculated or derivedfrom the received FP optical pressure sensor data.

In practice, pressure waveforms and pressure values vary from patient topatient and may be dependent on a number of factors, such as, whether ornot the patient has a healthy or diseased heart, or other conditionsthat may affect functioning of the heart. Skilled medical practitionerswill recognize characteristic variations in each pressure waveform andassociated pressure values, indicative of e.g. valvular stenosis orother patient physiology. For example, in use of dual sensor systemcomprising a sensor catheter and a sensor guidewire, concurrent pressuremeasurements from two FP optical pressure sensors enable thecardiologist to directly compare pressure waveforms and hemodynamicparameters, in real-time, to assess functioning of the heart valve. Forexample, the aortic regurgitation index (ARi) is an important parameterfor assessing functioning of the aortic valve. The ARi is computed frommeasured values of the left ventricular end-diastolic pressure (LVEDP),diastolic blood pressure (DBP), and systolic blood pressure (SBP), whichis defined as:

ARi=((DBP−LVEDP)/SBP)×100

Examples: Use of Dual Sensor System for TAVR and TMVR

FIG. 12 shows a schematic diagram to illustrate deployment of a dualsensor system of the first embodiment comprising a sensor catheter 300for measurement of pressure in the ascending aorta (Ao) and a sensorguidewire 200 for concurrent measurement of pressure in the leftventricle (LV), and in which the controller 100 is connected to adedicated user interface, e.g. a tablet PC 500, for displaying pressurewaveforms and associated hemodynamic parameters including an aorticregurgitation index (ARi). FIG. 12 includes schematic examples of screenshots indicative of a) a healthy heart, as represented by screenshot500-1 and b) a heart with significant aortic regurgitation, asrepresented by screenshot 500-2. In this example, the calibratedpressure data is also output via analog ports of controller 100 to aBP-22 PCM 400, e.g. for further processing or display of data by otherequipment, such as the large screen monitors, as typically used in aCath Lab.

A schematic partial cross-sectional diagram of a human heart 600-1 isshown in FIG. 13 to illustrate placement of the sensor catheter 300 andsensor support guidewire 200 of the dual sensor system of the firstembodiment for diagnostic measurements of hemodynamic parameters. Thedistal region of sensor support guidewire 200 is positioned forcontinuous blood pressure measurement by FP optical pressure sensor 230(P1) within the left ventricle (LV) 601. The sensor catheter 300 ispositioned for concurrent and continuous measurement of blood pressureby sensor 330 (P2) positioned within the ascending aorta 602, downstreamof the aortic valve 604, i.e. with the pigtail of the sensor catheter300 positioned close to the cusps of the aortic valve 604, and apertures335 arranged for injection of contrast medium into the ascending aorta602 downstream of the aortic valve 604. The sensor catheter 300 replacesa conventional pigtail catheter that is in place for contrast mediuminjection during TAVR and preferably has the same outer diameter, andother physical characteristics, of a conventional pigtail catheter ofthis type, so it may be used interchangeably without change ofprocedure, other than connecting the optical connector directly orindirectly to the control unit (e.g. control unit 100 shown in FIG. 1)when activation of the FP optical pressure sensor 330 P2 for pressuremeasurements is required. The tip 206 of the sensor support guidewire200 is introduced through the descending aorta 603, the ascending aorta602 and through aortic valve 604 in the manner of a conventional supportguidewire for TAVR. The preformed curved tip 206 anchors the sensorguidewire in the left ventricle 601 and positions the sensor 230 withinthe left ventricle, upstream of the aortic valve 604, as illustratedschematically. Thus, the FP optical pressure sensors 230 (P1) and 330(P2) are positioned so that one sensor is located upstream of the aorticvalve and one sensor located downstream of the aortic valve. Thisarrangement enables concurrent blood pressure measurements in theascending aorta and in the left ventricle, e.g., for measurement of atransvalvular pressure gradient across the aortic valve and otherhemodynamic parameters. In use of a dual sensor system comprising asensor guidewire and a sensor catheter as illustrated schematically inFIG. 13, which are independently movable, the relative positions of thetwo sensors 230 and 330 may be adjusted to some extent, depending on apatient's size and individual anatomy.

A schematic partial cross-sectional diagram of a human heart 600-2 isshown in FIG. 14 to illustrate placement of the dual sensor guidewire1200 of the second embodiment for diagnostic measurements of hemodynamicparameters within the left heart. The tip 1206 of the sensor supportguidewire 1200 is introduced through the descending aorta 603, theascending aorta 602 and through aortic valve 604 in the manner of aconventional support guidewire for TAVR. As illustrated schematicallythe helical spiral tip 1206 anchors the sensor guidewire in the leftventricle 601, with the first optical pressure sensor 1230-1 (P1)located within the left ventricle 601. The second optical pressuresensor 1230-2 (P2) is positioned in the ascending aorta 602. Forexample, a sensor spacing of about 20 mm to 50 mm would be sufficient toplace one sensor upstream and one downstream of a heart valve. However,blood pressure measurements may be affected by significant turbulence inthe blood flow through the cardiac cycle. For this reason, a largerspacing, e.g. 70 mm to 100 mm, between the two sensor locations may bepreferred to enable one sensor to be located further into the leftventricle 601 and another sensor to be located further upstream of theaortic valve 604 in the aorta 602, so that both sensors are located inregions of less turbulent flow, i.e. spaced some distance each side ofthe aortic valve 604. For example, based on review of CT scans to assessdimensions of the heart of a number of subjects, an 80 mm spacing of twopressure sensors may typically be required, e.g., to enable measurementof a transvalvular pressure gradient. For paediatric use, a smallergauge sensor guidewire and closer spacing of the sensors may beappropriate.

A schematic partial cross-sectional diagram of a human heart 600-3 isshown in FIG. 15 to illustrate placement of the sensor catheter 300 andsensor guidewire 200 of the dual system, for measurements of hemodynamicparameters, including concurrent measurements of blood pressure in theascending aorta and LV during TAVR. The tip 206 of the sensor supportguidewire 200 is introduced through the descending aorta 603, theascending aorta 602 and through aortic valve 604. In this example, thedistal region of the sensor catheter 300 is positioned with sensor 330(P2) in the aorta 602 and the distal region of the sensor guidewire 200is positioned with the sensor 230 (P1) in the left ventricle 601,similar to the arrangement shown in FIG. 13. Apertures 335 in the sensorcatheter provide for injection of contrast medium into the ascendingaorta. A catheter 700 carrying a valve delivery device 702 is mountedover the sensor guidewire 200, and is shown with the nose cone 701 ofthe valve delivery device 702 positioned through the aortic valve 604ready for deployment of a prosthetic aortic valve. Even when the valvedelivery device is this position during valve deployment, the firstoptical pressure sensor 230 (P1) of the sensor support guidewire ispositioned to enable continuous measurement of the LV pressure and thesecond optical pressure sensor 330 (P2) of the sensor catheter ispositioned to enable continuous measurement of the Aortic pressure.Since the catheter 700 of the valve delivery device 702 is mounted overthe sensor guidewire 200 in the aorta, if the sensor guidewire 200 isprovided with an optional second sensor as shown in FIG. 14, the secondsensor in the aorta would be covered by the catheter 700 at this stagein valve deployment. During this time, the optional second sensor of thesensor guidewire would be blocked or disabled from measuring bloodpressure in the aorta. This application of the dual sensor systemcomprising a sensor guidewire 200 and a sensor catheter 300 enablespressure measurements in the left ventricle and in the ascending aortabe monitored on demand during TAVR, and potentially continuously,before, during and after valve deployment.

In this disclosure, enabling “continuous” measurements of blood pressurerefers to enabling “on demand” sampling of blood pressure measurementsat any time during a TVT procedure. A typical heart rate is e.g., 60 to120 beats per minute. Typically, the digital signal conditioner for thefirst and second FP optical pressure sensors use a much faster samplingrate, e.g., 250 Hz, to generate digital pressure waveforms for bloodpressures for LV and Ao. These digital pressure waveforms, and derivedparameters, may be output to a digital monitor for display and furtheranalysis. To enable interfacing to a BP-22 compliant PCM, the controlunit comprises a signal converter that converts the digital waveformsand generates analog input and output signals for interfacing to a BP-22compliant PCM.

FIGS. 13 to 15 show examples of an aortic approach to the left ventricle601, which is the most commonly used approach for TAVR e.g. using eithertransfemoral or transradial percutaneous entry for left heartcatheterization. Alternatively, in some patients, an apical approach forTAVR may be used (not shown in the drawings), where a small incision ismade between the ribs to allow the sensor guidewire and valve deliverydevice to be inserted into the heart through the apex of the leftventricle. Since the latter is a more direct approach, a shorter sensorguidewire and valve delivery device may be used; the length, diameter,stiffness and other characteristics of the sensor guidewire aretherefore selected accordingly.

An example of an apical approach to the left ventricle 601, i.e. throughapex 607 of the left ventricle 601, to access the mitral valve 606 forTMVR is shown in FIG. 16, which shows a schematic partialcross-sectional diagram 600-4 of a human heart to illustrate placementof the sensor catheter 300 and sensor guidewire 200 of dual sensorsystem, for measurements of hemodynamic parameters, including concurrentmeasurements of blood pressure in the LV 601 and left atrium (LA) 614during TMVR. As illustrated schematically in FIG. 16, in this example,the tip 206 of sensor guidewire 200 is introduced through the apex 607of the LV 601 and passed through the mitral valve 606 into the LA 614,for measurement of LA pressure by pressure sensor 230 (P1) positioned inthe LA. The sensor catheter 300 is inserted through the descending aortainto the ascending aorta 602, and the tip of the catheter is advancedthrough the aortic valve 604 into the LV 601 for injection of contrastmedium into the LV 601 through apertures 335, and for measurement of LVpressure by pressure sensor 330 (P2). A catheter 700 carrying mitralvalve delivery device 702 is delivered over the sensor support guidewire200 and positioned through the mitral valve 606. This arrangement allowsfor blood pressure monitoring in the LV and LA during TMVR.

For comparison, a schematic partial cross-sectional diagram 600-5 isshown in FIG. 17 to illustrate placement of the sensor catheter 300 andsensor guidewire 200 using a trans-septal approach, via the inferiorvena cava 620 and the right atrium 621, via a trans-septal puncture toenter the LA 614 and LV 601 for TMVR. In this example, the tip of thesensor catheter 300 is positioned in the LA 614 for measurement of LApressure by pressure sensor 330 (P2). The tip 206 of the sensorguidewire 200 is positioned in the LV 601 for measurement of LV pressureby pressure sensor 230 (P1). Catheter 700 carrying valve delivery device702 is delivered over the sensor support guidewire 200 to position thevalve delivery device through the mitral valve 606.

A schematic partial cross-sectional diagram 600-6 is shown in FIG. 18 toillustrate placement of the sensor catheter 300 and sensor guidewire 200of the dual sensor system using an aortic approach to the LV and LA forTMVR. The tip 206 of the sensor guidewire 200 is inserted through theaorta, through the aortic valve into the LV 601 and then advancedthrough the mitral valve 606 into the LA to position pressure sensor 230(PA) in the LA for measurement of LA pressure. The sensor catheter 300is introduced through the aorta, and through the aortic valve formeasurement of LV pressure by pressure sensor 330 (P2), and injection ofcontrast medium through apertures 335. The catheter 700 carrying thevalve delivery device 702 is inserted over the sensor support guidewire200 to position the valve delivery device through the mitral valve 606.

FIG. 19 shows a schematic partial cross-sectional diagram 600-7 showingplacement of a dual sensor support guidewire 1200 through the inferiorvena cava 620 and the RA 621 for a trans-septal approach to the LA 614and LV 601 for TMVR. In this example, the tip 1206 of the sensor supportguidewire 1200 is positioned in the LV 601 for measurement of the LVpressure by pressure sensor 1230-1 (P1). Catheter 700 and valve deliverydevice 702 are mounted over the sensor support guidewire 1200 toposition the valve delivery device through the mitral valve 606. Thepressure in the left atrium 614 may be obtained by a second opticalsensor 1230-2 (P2) in the sensor support guidewire 1200 positioned inthe LA 614, i.e., measurements made before introducing or afterwithdrawing the valve delivery device 702. Alternatively, the LApressure may be obtained indirectly from a pulmonary wedge pressuremeasurement made with a pulmonary artery (PA) catheter.

Regarding pressure ranges to be measured within the aorta and chambersof the heart, the peak pressure in the LV may be around 150 mmHg ormore, so for absolute pressure measurements, pressure sensors capable ofdirectly measuring blood pressure in the range of 0 to ˜300 mmHg aresuitable. For assessing heart valve function, accurate measurement ofsmaller differences in blood pressure is required to assess atransvalvular pressure gradient. For example, considering atransvalvular pressure gradient across the aortic valve, in a healthyheart, this pressure difference would be close to zero, or e.g., <5mmHg. A pressure difference measured in the LV and ascending aorta (Ao)in the range of e.g., >40 mmHg to 60 mmHg, would be indicative of severeaortic valve stenosis. During TAVR to deploy a prosthetic aortic valve,if a measurement of the aortic transvalvular pressure gradient is madebefore and after deployment and positioning of a prosthetic aorticvalve, if the valve deployment is successful, it would be expected tosee a significant decrease in the transvalvular pressure gradient, e.g.from >40 mmHg to <10 mmHg if valve placement is optimal. Forrepositionable prosthetic valves, measurements of the transvalvularpressure gradient when the prosthetic valve is first positioned, andthen repositioned to achieve a lower pressure gradient, may provideadditional data to assist in optimal placement of the prosthetic valve.Thus, for TAVR, while measurement of transvalvular pressure gradients inthe range of 0 to 60 mmHg within ±2 mmHg is desirable, measurementwithin ±10 mmHg may be adequate to assess aortic valve function beforeand after TAVR, e.g., to show a significant reduction in transvalvularpressure gradient from >40 mmHg before TAVR to <20 mmHg or <10 mmHgafter deployment of prosthetic valve. To improve the accuracy oftransvalvular pressure measurements with the pair of FP optical pressuresensors, it is beneficial if the first and second FP pressure sensorsare “zeroed” relative to each other by taking simultaneous pressuremeasurements with both first and second FP optical pressure sensorsplaced within one chamber of the heart, e.g. with both sensors placedwithin the LV measuring the same pressure concurrently.

In comparison, for the mitral valve, it is required to measure apressure gradient with greater accuracy. For example, a transvalvularpressure gradient of 20 mmHg would be indicative of severe mitral valvestenosis or other severe mitral valve malfunctioning. Thus, a mitralvalve transvalvular pressure gradient of >5 mmHg may be indicative ofmitral valve stenosis. For this reason, assessment of mitral valvefunction requires measurement of a transvalvular pressure gradientwithin ±2 mmHg, and preferably within ±1 mmHg is desirable. As mentionedabove, to improve the accuracy of transvalvular pressure measurements,it is beneficial if the first and second FP pressure sensors are“zeroed” relative to each other by taking simultaneous baseline pressuremeasurements with both first and second FP sensors positioned within onechamber of the heart, if possible in the LA, or alternatively in the LV.

The optical pressure sensors 230 and 330 (P1 and P2) are preferablyFabry-Pérot (FP) Micro-Opto-Mechanical System (MOMS) sensors, such asthose described by FISO Technologies (E. Pinet, “Pressure measurementwith fiber-optic sensors: Commercial technologies and applications” 21stInternational Conference on Optical Fiber Sensors, edited by Wojtek J.Bock, Jacques Albert, Xiaoyi Bao, Proc. of SPIE Vol. 7753, (2011)).These optical pressure sensors comprise an optical fiber having a FPMOMS sensor at the sensor end of the fiber for sensing pressure. By wayof example, for standard diameter optical fibers, each fiber has adiameter of 0.155 mm (0.006 inch) and each optical pressure sensor has adiameter of 0.260 mm (0.010 inch). FP optical pressure sensors capableof pressure measurements in a range suitable for medical applicationsand blood pressure measurements are also available from Opsens Inc.

For smaller fibers, e.g. 0.100 mm fibers, and smaller diameter sensors,the dimensions of the sensor lumen of the sensor catheter and the insidediameter of inner tubular layer of the sensor guidewire may be reducedin size accordingly.

Since the sensor guidewires and sensor catheters of the embodiments areintended for single-use only, preferably the optical connectors forconnection to the control unit are standard low cost optical connectors.Similarly, the flexible tubing, and other connectors for the other portsare preferably standard materials and components, such as luer fittingsor other medical standard fluid ports, as appropriate, which can besterilized, and so that the sensor catheter and sensor guidewire can beprovided in single-use sterile packaging, using conventional processesfor packaging and sterilization of medical devices.

As mentioned above, it is desirable that the sensor guidewire hasmechanical characteristics, such diameter, stiffness and torquecharacteristics, similar to a conventional support guidewire for TVT.The optical fiber and optical pressure sensor do not add significantstiffness to the sensor guidewire, and thus these characteristics areprimarily determined by structure and materials of the sensor guidewire,e.g. the inner tubular layer which may be a stainless steel hypotube orpolymer layer and the outer tubular layer which may be an outerstainless steel hypotube or stainless steel micro-coil or a combinationthereof. The inner tubular layer may comprise a multilayer structure.Similarly, the outer tubular layer may also comprise a multilayerstructure.

As mentioned above, it is desirable that the sensor catheter hasmechanical characteristics, such diameter, stiffness and flexibility,similar to a conventional pig-tail catheter used for injection ofcontrast agent and other fluids. The optical fiber and optical pressuresensor do not add significant stiffness to the sensor catheter, and thusthese characteristics are primarily determined by the type of materialand wall thickness used for the multi-lumen catheter tubing.

Other factors for consideration are: regulatory requirements for medicaldevices, ease of use and safety. For these reasons, it is desirable thatthe materials for fabrication of sensor guidewire and sensor catheterare based on a conventional tried and tested medical devices, i.e. basedon a predicate device structure which has regulatory approval and whichis fabricated with materials and components which already have FDAand/or CE mark regulatory approval.

It will be appreciated that in alternative embodiments or variants ofthe dual sensor system of the embodiments described in detail above,different combinations of one or more features disclosed herein, andfeatures disclosed in the related patent applications referenced herein,may provide further alternative embodiments.

As disclosed herein, in one embodiment, the cardiologist is offered dualsensor system comprising a TVT support guidewire containing a firstoptical pressure sensor (sensor support guidewire) and an angiographicpigtail catheter containing a second optical pressure sensor (sensorcatheter), which has particular application for continuous bloodpressure measurements during TVT, e.g. TAVR or TMVR, wherein the pair ofoptical pressure sensors are configured for monitoring and diagnosticmeasurements of hemodynamic parameters, including concurrent measurementof blood pressure at two different and variable locations within theheart and aorta during left heart catheterization. The interventionalcardiologist may adjust the relative positioning of the sensor catheterand the sensor guidewire so that the first and second optical pressuresensors are positioned to suit the dimensions of an individual's heart,and are appropriately positioned for relative to the heart valve.Radiopaque markers on the sensor guidewire and sensor catheter may beprovided to assist in positioning of the first and second FP opticalsensors. A dual sensor system comprising single sensor guidewire used inconjunction with a single sensor catheter may offer a morecost-effective solution, which is more readily fabricated thanmultisensor guidewires and multisensor catheters.

If required a second sensor may be provided in a sensor guidewire. Thus,in another embodiment, a dual sensor system comprises a dual sensorguidewire for diagnostic measurements during left heart catheterization.The dual sensor guidewire may be used with the same two channelcontroller as described above.

In other applications of a TVT support guidewire containing a first FPoptical pressure sensor, the TVT support guidewire is positioned forcontinuous direct measurement of LV pressure in the left ventricleduring TVT, e.g. during TAVR or BAV. A second pressure measurement maybe obtained using another type of pressure sensor placed in theascending aorta, e.g. a fluid filled catheter with an external pressuresensor, or a catheter with an electrical pressure sensor. For TMVR, thepressure in the left atrium may be obtained indirectly by using apulmonary artery (PA) catheter to obtain a pulmonary wedge pressure.

Systems and apparatus according to embodiments of the present inventiondescribed herein offer real-time hemodynamic valve function data to thecardiologist during TAVR. The first and second optical pressure sensorsprovide accurate measurements of blood pressure concurrently at twopositions, i.e. in the left ventricle and in the ascending aorta. Ifrequired, the pressure measurements can be provided continuously, i.e.at any time throughout the TAVR procedure. In practice, pressuremeasurements may be made continually, e.g. periodically or at intervalsbefore, during or after a TVT procedure. For example, the system enablesuninterrupted monitoring of the LV pressure by the first sensor in thesensor support guidewire and the second pressure sensor in the sensorcatheter can provide uninterrupted pressure measurements in theascending aorta even during balloon valvuloplasty and valve deployment,when the part of the sensor guidewire downstream of the aortic valve issurrounded by a guide catheter, balloon catheter, valve delivery deviceor other components.

With the introduction of prosthetic valves that are repositionableduring TVT, pressure measurements during TVT could potentially providedata on valve function at the point of deployment to assist inoptimizing valve placement, to mitigate issues of sub-optimal valveplacement, such as regurgitation or paravalvular leakage.

Advantageously, the sensor catheter has the external form and dimensionsof a conventional pigtail catheter which is typically already in placein the aorta during TAVR, i.e. for delivery of contrast medium into theaorta and LV near the aortic valve. Externally, the sensor guidewireresembles a conventional support guidewire, having appropriatedimensions, stiffness and torque characteristics, and functionality toenable the sensor guidewire to be used in a conventional manner as asupport guidewire for TAVR. Thus, apart from the need to make theoptical connections for the sensor catheter and sensor guidewire to thecontrol unit for activation of the optical pressure sensors, the sensorpigtail catheter can be introduced and used in same manner as aconventional angiographic pigtail catheter, and the sensor guidewire canbe introduced and deployed in the same manner as a conventional supportguidewire. Each of the sensors can provide pressure data continuously,or at intervals as needed during TAVR, without disrupting the standardTAVR procedure. With a suitably configured interface, the controllerprovides compatibility with standard PCM systems, and thus can beintegrated more readily into the Cath Lab, with less equipment clutter,and avoiding additional cabling.

For some applications, such as diagnostic measurements to assess heartvalve function, it may be desirable to provide a dual sensor guidewire,such as sensor guidewire 1200 described above. However, providing two ormore optical pressure sensors within a support guidewire adds to costand manufacturing complexity. Since a pigtail catheter is typically inplace during TVT for delivery of contrast medium, providing one sensorin the pigtail catheter and one sensor in the support guidewirepotentially offers a lower cost system. Further cost reductions areoffered when the controller is configured to interface directly withstandard operating room and Cath Lab monitoring systems, therebyavoiding the need for a dedicated stand-alone monitoring unit.

TABLE 2 Abbreviations or acronyms ARi or AR Index Aortic RegurgitationIndex BAV Balloon Aortic Valvuloplasty Cath Lab Cardiac CatheterizationLaboratory CE Mark ‘Conformité Européenne’, a European certificationmark DBP Diastolic Blood Pressure FP MOMS Sensor Fabry-PérotMicro-Opto-Mechanical- System Sensor ICU Intensive Care Unit LVEDP LeftVentricular End-Diastolic Pressure OR Operating Room RA Right Atrium RVRight Ventricle SBP Systolic Blood Pressure TAVI or TAVR TranscatheterAortic Valve Implantation or Replacement TMVI or TMVR TranscatheterMitral Valve Implantation or Replacement TVR Transcatheter heart ValveReplacement TVT Transcatheter Valve Therapies LV Left Ventricle LA LeftAtrium FDA Food and Drug Administration EEPROM Electrically ErasableProgrammable Read- Only Memory AAMI Association for the Advancement ofMedical Instrumentation ANSI American National Standards Institute ANSIBP-22 Standards document ANSI/AAMI BP22: 1994/(R)2016 relating toperformance and safety requirements for transducers, including cables,designed for blood pressure measurements through an indwelling catheteror direct puncture.

INDUSTRIAL APPLICABILITY

Dual sensor systems comprising sensor catheters and sensor guidewiresaccording to embodiments disclosed herein are configured to providereal-time, concurrent, pressure measurements at two locations duringTAVR, other TVT procedures and for diagnostic measurements ofhemodynamic parameters to assess heart function. A pair of opticalpressure sensors enables two pressure measurements to be takenconcurrently, i.e. using similar FP optical pressure sensors in the botha sensor catheter and a sensor support guidewire. For example, thesensor guidewire has the same physical characteristics, such asstiffness, of a support guidewire for TAVR, and the sensor catheter hasthe form of an angiographic catheter which is conventionally placed inthe aorta for injection of contrast medium. Blood pressure measurementscan be obtained continually during TAVR by placement of the sensorguidewire to position the first optical pressure sensor in the LV for LVpressure monitoring, and placement of the sensor catheter to positionthe second optical pressure sensor within the aorta downstream of theaortic valve for Aortic pressure monitoring. Pressure measurements maybe made continuously or at intervals on demand during TAVR. Thecontroller may be configured to interface directly with ANSI BP-22compliant patient monitoring systems. For some applications, a dualsensor support guidewire is provided.

Although embodiments of the invention have been described andillustrated in detail, it is to be clearly understood that the same isby way of illustration and example only and not to be taken by way oflimitation, the scope of the present invention being limited only by theappended claims.

1. A dual sensor system for monitoring blood pressure at first andsecond locations during transcatheter valve therapy (TVT), comprising: acontroller; a sensor support guidewire for TVT comprising a tubularmember having a length extending between a proximal end and a distalend, the distal end comprising an atraumatic pre-formed curved flexibledistal tip, the tubular member containing a first optical fiberextending within the sensor support guidewire from an opticalinput/output connector at the proximal end of the sensor supportguidewire to a first Fabry-Pérot (FP) optical pressure sensor, the firstFP optical pressure sensor being positioned within a distal region ofthe tubular member, near the distal tip, and a sensor aperture in thesensor support guidewire adjacent the first optical FP pressure sensorfor fluid contact therewith; a sensor angiographic catheter comprising alength of multi-lumen catheter tubing extending between a proximal endand a distal end and comprising a first lumen and a second lumen, thedistal end comprising a preformed pigtail distal tip, and the cathetertubing having at its proximal end a connection hub comprising a firstport for the first lumen and a second port for the second lumen, asecond optical fiber extending within the first lumen from anoptical/input output connector of the first port to a second FP opticalpressure sensor, the second FP optical pressure sensor being positionedwithin a distal region of the first lumen near the distal tip, and asensor aperture in first lumen of the catheter tubing near the FPoptical pressure sensor for fluid contact therewith; the second portcomprising an injection port for injection of fluid into the secondlumen, and the second lumen comprising a plurality of apertures forfluid ejection along a length of the distal region between the sensoraperture and the distal tip; the controller comprising an opticalcontrol unit comprising optical input/output ports for coupling to theoptical input/output connectors of the sensor support guidewire and thesensor angiographic catheter and a light source and detector foroperating the first and second FP optical pressure sensors andprocessing optical data from the first and second FP optical pressuresensors to generate data indicative of blood pressure; a processor,memory, hardware and/or software components for generating at least oneof analog and digital data comprising first and second pressurewaveforms; and a communications interface comprising ports forinterfacing with at least one of a patient monitoring system and otherperipherals.
 2. The dual sensor system of claim 1, configured formeasurements of hemodynamic parameters during Transcatheter Aortic ValveReplacement (TAVR), wherein: the flexible distal tip of the sensorsupport guidewire comprises a preformed curved tip configured forpositioning within the left ventricle and the first FP optical pressuresensor (P1) is a distance L1 from the flexible distal tip of the sensorsupport guidewire for positioning of P1 within the left ventricle duringTAVR; and the sensor angiographic catheter comprises a dual lumenpigtail catheter wherein said plurality of apertures in the second lumennear the pigtail distal tip are arranged for injection of contrastmedium into the aorta, and the second FP optical pressure sensor (P2) islocated in a distal region of the first lumen of the sensor angiographiccatheter a distance L2 from the pigtail tip for positioning of P2 in theascending aorta, downstream of the aortic valve, during TAVR.
 3. Thedual sensor system of claim 1, configured for measurements ofhemodynamic parameters during Transcatheter Mitral Valve Replacement(TMVR), wherein: the first FP optical pressure sensor (P1) is located adistance L1 from the flexible distal tip of the sensor support guidewirefor positioning of P1 within a first heart chamber on one side of themitral valve during TMVR; the second FP optical pressure sensor (P2) islocated in the first lumen of the sensor catheter a distance L2 from thepigtail tip for positioning of P2 in a second heart chamber, on anopposite side of the mitral valve during TMVR; and said plurality ofapertures in the second lumen near the pigtail tip are arranged forinjection of contrast medium into the second heart chamber.
 4. The dualsensor system of claim 2, wherein the first and second FP opticalpressure sensors are a pair of similar FP optical pressure sensorsconfigured for measuring a blood pressure gradient across the aorticvalve during TAVR in a range of 0 mmHg to 60 mmHg within ±10 mmHg orless.
 5. The dual sensor system of claim 3 wherein first and second FPoptical pressure sensors are a pair of similar FP optical pressuresensors configured for measuring a blood pressure gradient across themitral valve during TMVR in a range of 0 to 20 mmHg within ±2 mmHg orless.
 6. The dual sensor system of claim 1, wherein the TVT sensorsupport guidewire has stiffness characteristics along its lengthconfigured for over-the-guidewire mounting of a prosthetic valvedelivery device, said stiffness characteristics of a distal region foruse during valve deployment being in a range of stiffnesscharacteristics of support guidewires of a group comprising a Safari™guidewire, a Confida™ guidewire and an Amplatz™ Super Stiff Guidewire.7. The dual sensor system of claim 1, wherein the TVT sensor supportguidewire has stiffness characteristics along its length configured forover-the-guidewire mounting of a prosthetic valve delivery device, saidstiffness characteristics of a distal region for use during prostheticvalve deployment being defined by a flexural modulus in a range of 17GPa to 158 GPa.
 8. The dual sensor system of claim 1, wherein the TVTsensor support guidewire has a maximum outside diameter of ≤0.89 mm(0.035 inch) and a length in a range from 1 m to 3 m.
 9. The dual sensorsystem of claim 1, wherein the optical input/output connector of thefirst port of the sensor angiographic catheter comprises a separableoptical connector and a flexible optical coupling comprising a length ofoptical cable, the separable optical connector detachably connecting thesensor angiographic catheter to one end of the optical cable, and theoptical cable having at its other end an optical connector forconnection to the control system.
 10. The dual sensor system of claim 1,wherein the optical input/output connector at the proximal end of theTVT sensor support guidewire comprises a separable optical connector anda flexible optical coupling comprising a length of optical cable, theseparable optical connector detachably connecting the TVT sensor supportguidewire to one end of the optical cable, and the optical cable havingat its other end an optical connector for connection to the controlsystem.
 11. The dual sensor system of claim 10, wherein forover-the-guidewire mounting of components from the proximal end of theTVT sensor support guidewire, the separable optical connector comprisesan optical micro-connector having male and female parts, wherein thesensor support guidewire comprises the male part of the opticalmicro-connector, which has a diameter no greater than a maximum outsidediameter the TVT sensor support guidewire.
 12. The dual sensor system ofclaim 11, wherein the flexible optical coupling comprises the femalepart of the optical micro-connector, which forms a connector handle formanipulating the TVT sensor support guidewire.
 13. The dual sensorsystem of claim 1, wherein the sensor support guidewire comprise aradiopaque marker near the first FP optical pressure sensor, and thesensor catheter comprises a radiopaque marker near the second FP opticalsensor and at the distal tip, and optionally, radiopaque markers areplaced at regular intervals along the length of the sensor catheter andsensor support guidewire, so that, in use, relative positioning orspacing of the first and second FP optical pressure sensors of thesensor catheter and the sensor support guidewire can be determined. 14.A TVT sensor support guidewire for the dual sensor system of claim 1,comprising a tubular member having a length extending between a proximalend and a distal end, the distal end comprising a flexible distal tip,the tubular member comprising an outer tubular member and an innertubular member, the inner tubular member inserted within the outertubular member, and an optical fiber extending within the inner tubularmember from an optical input/output connector at the proximal end of thesensor support guidewire to a FP optical pressure sensor, the FP opticalpressure sensor being positioned within a distal region of the sensorsupport guidewire, near the flexible distal tip, a sensor aperture inthe tubular member adjacent the first FP optical pressure sensor forfluid contact therewith, and the flexible distal tip comprising apre-formed curved tip.
 15. The TVT sensor support guidewire of claim 14,wherein the inner tubular member comprises a first stainless steelhypotube having physical characteristics providing a predeterminedstiffness and flexibility to act as a core of the TVT sensor supportguidewire and the outer tubular member comprises one of a secondstainless steel hypotube, a flexible spiral wound micro-coil, and acombination thereof.
 16. The TVT sensor support guidewire of claim 15,wherein the inner tubular member acts as a core tube to provide arequired stiffness along the length of the sensor support guidewire, andthe outer tubular member is generally more flexible along most of itslength.
 17. The TVT sensor support guidewire of claim 14, wherein at thesensor position, the sensor aperture comprises a first sensor aperturein the outer tubular member and a second sensor aperture in the innertubular member, the outer tubular member comprising a reinforced stifferregion around the sensor aperture.
 18. The TVT sensor support guidewireof claim 14, wherein at the sensor position, the sensor aperturecomprises a first sensor aperture in the outer tubular member, and aregion of the inner tubular member which is partially cut away to form acavity around the optical pressure sensor, the outer tubular layercomprising a reinforced stiffer region extending around the sensoraperture.
 19. The TVT sensor support guidewire of claim 14, furthercomprising a second FP optical pressure sensor and second optical fibercontained within the inner tubular member, the second FP opticalpressure sensor being positioned proximally of the first opticalpressure sensor, and wherein the inner tubular member has an apertureadjacent the second optical pressure sensor, or is partially cut away toform a cavity around the second optical pressure sensor, and the outertubular layer comprises a second sensor aperture adjacent the secondoptical pressure sensor and a reinforced region around the second sensoraperture adjacent each sensor.
 20. The TVT sensor support guidewire ofclaim 19, wherein the first and second FP optical pressure sensors arespaced apart by a distance L in the range from 20 mm to 100 mm.
 21. TheTVT sensor support guidewire of claim 14, having stiffnesscharacteristics along its length similar to stiffness characteristics ofa TVT support guidewire comprising one of a Safari™ guidewire, aConfida™ guidewire and an Amplatz™ Super Stiff guidewire.
 22. A sensorangiographic catheter for the dual sensor system of claim 1, comprisinga length of multi-lumen catheter tubing extending between a proximal endand a distal end and comprising a first lumen and a second lumen, thedistal end comprising a preformed pigtail distal tip, and the cathetertubing having at its proximal end a connection hub comprising a firstport for the first lumen and a second port for the second lumen, anoptical fiber extending within the first lumen from an optical/inputoutput connector of the first port to a FP optical pressure sensor, theFP optical pressure sensor being positioned within a distal region ofthe first lumen near the distal tip, and a sensor aperture in the sensorcatheter near the FP optical pressure sensor for fluid contacttherewith; and the second port comprising an injection port forinjection of fluid and the second lumen comprising a plurality ofapertures for fluid ejection along a length of the distal region nearthe distal tip between the sensor aperture and the distal tip.
 23. Thesensor angiographic catheter of claim 22 wherein the multi-lumencatheter tubing comprises dual lumen tubing having an outside diameterin the range from 4 French to 7 French, wherein the first lumen is sizedto accommodate the optical fiber and the FP optical pressure sensor andthe second lumen is sized for rapid injection of contrast medium. 24.The sensor angiographic catheter of claim 23, wherein the second lumenis sized to act as a guidewire lumen for insertion of the sensorangiographic catheter over a guidewire.
 25. The sensor angiographiccatheter of claim 22, wherein the catheter tubing further comprises oneor more additional lumens, and the connection hub further comprises acorresponding number of additional ports.
 26. The sensor angiographiccatheter of claim 22, further comprising a radiopaque marker near the FPoptical pressure sensor and a radiopaque marker at the distal tip of thesensor catheter.
 27. A controller for the dual sensor system of claim 1,comprising: an optical control unit comprising a light source anddetector, and an optical interface for coupling, via respective opticalinput/output ports, to each of the optical input/output connectors ofthe TVT sensor support guidewire containing the first FP opticalpressure sensor and the angiographic catheter containing the second FPoptical pressure sensor; data storage and processing means configuredfor processing optical data indicative of pressure values, andoutputting at least one of digital and analog signals to ports of acommunications interface, for coupling to a patient monitoring systemand other peripherals.
 28. The controller of claim 27, for connection toa patient care monitor (PCM) configured for receiving analog signalsindicative of blood pressure compliant with the ANSI BP-22 Standard, thecontroller comprises a BP-22 signal converter, and wherein thecommunications interface comprises ports for respective analog signaloutputs from each of the optical pressure sensors and analog controlsignal inputs.
 29. A kit comprising components for use with a dualsensor system for monitoring blood pressure at first and secondlocations during transcatheter valve therapy (TVT), comprising: a firstcomponent comprising: a sensor support guidewire for TVT comprising atubular member having a length extending between a proximal end and adistal end, the distal end comprising an atraumatic pre-formed curvedflexible distal tip, the tubular member containing a first optical fiberextending within the sensor support guidewire from an opticalinput/output connector at the proximal end of the sensor supportguidewire to a first Fabry-Perot (FP) optical pressure sensor, the firstFP optical pressure sensor being positioned within a distal region ofthe tubular member, near the distal tip, and a sensor aperture in thesensor support guidewire adjacent the first optical FP pressure sensorfor fluid contact therewith; a second component comprising: a sensorangiographic catheter comprising a length of multi-lumen catheter tubingextending between a proximal end and a distal end and comprising a firstlumen and a second lumen, the distal end comprising a preformed pigtaildistal tip, and the catheter tubing having at its proximal end aconnection hub comprising a first port for the first lumen and a secondport for the second lumen, a second optical fiber extending within thefirst lumen from an optical/input output connector of the first port toa second FP optical pressure sensor, the second FP optical pressuresensor being positioned within a distal region of the first lumen nearthe distal tip, and a sensor aperture in first lumen of the cathetertubing near the FP optical pressure sensor for fluid contact therewith;the second port comprising an injection port for injection of fluid intothe second lumen, and the second lumen comprising a plurality of fluidapertures along a length of the distal region between the sensoraperture and the distal tip; and wherein the first and second FP opticalpressure sensors are pair of similar FP optical pressure sensors. 30.The kit of claim 29, wherein the optical input/output connector of thefirst port of the sensor angiographic catheter comprises a separableoptical connector and a flexible optical coupling comprising a length ofoptical cable, the separable optical connector detachably connecting thesensor angiographic catheter to one end of the optical cable, and theoptical cable having at its other end an optical connector forconnection to controller; and the optical input/output connector at theproximal end of the TVT sensor support guidewire comprises a separableoptical connector and a flexible optical coupling comprising a length ofoptical cable, the separable optical connector detachably connecting theTVT sensor support guidewire to one end of the optical cable, and theoptical cable having at its other end an optical connector forconnection to the controller; and wherein for over-the-guidewiremounting of components from the proximal end of the TVT sensor supportguidewire, the separable optical connector comprises an opticalmicro-connector having male and female parts, wherein the sensor supportguidewire comprises the male part of the optical micro-connector, whichhas a diameter no greater than a maximum outside diameter of the TVTsensor support guidewire, and the flexible optical coupling comprisesthe female part of the optical micro-connector, which forms a connectorhandle for manipulating the TVT sensor support guidewire.
 31. The kit ofclaim 29 wherein the first and second FP optical pressure sensors areconfigured for measuring a transvalvular blood pressure gradient acrossan aortic valve during TAVR in a range of 0 mmHg to 60 mmHg within ±10mmHg or less.
 32. The kit of claim 29 wherein first and second FPoptical pressure sensors are configured for measuring a transvalvularblood pressure gradient across a mitral valve during TMVR in a range of0 mmHg to 20 mmHg within ±2 mmHg or less.